i noticed this competition relating to 3d printing and thought i should enter partly beacuse i would really like some of the prizes and also because i think that this instructable may help you to improve your 3d modelling and hence animation or 3d printing ability. i shall start with a guide to using sketchup, one of the easiest 3d modelling programs to use and also free to download. i then move on to explain some of the basics of how i use blender, also free but rather complex and highly versatile, i shall also discuss methods for exporting from sketchup to blender and also where good sources of free 3d models can be found.
finally i discuss the ABSOLUTE basics of blender(another 3d application) and how to use it to animate, render and 3D PRINT your sketchup models. i finish with a video example of a sketchup model once animated and a section on how to design models 3d printing. please vote me to win, thanks.

sketchup and blender are available here:

http://www.sketchup.com/download it has changed a bit since i downloaded it and i am not sure if sketchup make is the same as the old version but i assume it is, this is also available(seems more like the older version) http://www.sketchup.com/intl/en/download/gsu.html and there is this http://en.softonic.com/s/google-sketchup-8-free-download not sure about that one. if all else fails the old versions may still be available somewhere. i am quite confident that this works http://www.sketchup.com/intl/en/download/gsuwenthankyou.html you probably ought to read the stuff on the http://www.sketchup.com/intl/en/download/gsu.html page first though.
GIMP image editing software can also help for texturing but i will only be mentioning it here as a possible program for certain texture editing operations and will not describe how to use it.

http://www.blender.org/download blender is always being updated, older versions are available here http://download.blender.org/release/ and here http://www.blender.org/download/get-blender/older-versions/ however all the fundamental stuff should remain the same and still work as i describe.

below is a video showing some sketchup models of mine animated in blender

NOTE: when you first try to open sketchup it prompts you to choose a template, choose "simple, metres". this will also help when you are exporting to blender.

EXTRA NOTE: of this tutorial describes methods of 3d modelling and converting out of sketchup. it also explains how to use blender, if you are only interested in the parts relating directly to 3d printing they can be found in the final few pages. otherwise the rest should help you to make models the can be 3d printed if you have not done so already.

Step 1: Using Sketchup Part 1

the first thing you must understand when using a new 3d application is that it is 3D, the problem of course is the computer screen is only 2D. this means perhaps the first thing you should learn is the 3d view changing tools. when sketchup opens you find a basic 3d model of a cut out of a person, you should go to "view-->toolbars-->large tool set" and this brings up a panel on the left of the screen with all the tools.
the magnifying glass tool is used to zoom in and out by clicking and moving up or down.
the orbit tool lets you rotate around a central point by pulling whilst holding left click down from the direction you want to move in.
the hand tool lets you pan in the same way as the orbit tool lets you rotate, moving the camerawhilst stil facing in the same direction.
the eye tool lets you turn on the spot without  moving your viewpoint.
finally the magnifying glass with the arrows around it lets you zoom out, whilst still facing in the same direction, so you can see the whole model.

and as an extra notes under "edit-->group/component/line/face/entity-->zoom to extents" you can zoom to extents for an individual object rather than the whole model when the object in question is selected.

Step 2: Selecting and Deleting

this is as easy as it sounds, to select click the select tool then click on the surface, group,line,etc you want to select.
to select multiple entities hold down "shift" key while selecting, clicking on an already selected object should deselect it.
deleting is done either with the erase tool or by just pressing the backspace or delete key when the object you want to remove is selected. undo and redo are available under "edit-->" . multiple entities can also be selected by dragging the select tool to form a box around them, left to right dragging only selects objects fully within the box. right to left selects everything that has any part of itself in the box.

viewing angle is not saved in the way that geometry position and texturing are, undoing will not change camera position, to restore a previous camera position click on the magnifying glass with the leftward arrow. this only works for the last 5 or so viewing angles you have used.

Step 3: Starting to Model With Sketchup

modelling with sketchup is simple, you construct faces line by line which are then filled in by the program. you can texture these faces and apply different materials afterwards. you can also extrude and pull out faces to make box like shapes and use other tricks to form spheres or pipework. cones can be produced with  extrude, which i will explain later.

here is an example.
first use the rectangle or circle tool to form a flat surface. then select the surface and use the push-pull tool(box with arrow above) to drag it out along the direction at 90 degress to the planar surface. congratulations, your first 3d object. you can now use the viewing tools at the bottom of the large tool set to move around and view the 3d structure. 

please note that a brilliant feature of sketchup is that with many of the tools you can for example select a surface to push-pull or a centre point where you want to place a circle. then after that you can change your viewing position and angle and click back on the same tool you were just using, in many cases doing this will then allow you to set the distance from a different view point when push-pulling or set the radius of a circle to be at a point not visible in the view of it's centre.

the distance you extrude by can be entered as a number by typing "(a number)" then "enter" key or by holding shift and lining the extruded face up with an object or point along the axis you are extruding on.

Step 4: Drawing Out Complex 2D Shapes

ok, so far you have extruded a rectangle or circle. now i explain how to form more complex 2d shapes that can then be push-pulled. using the line tool create each edge until they form a closed figure, crucially all edges must be in the same plane. once you close the figure it should fill to form a face, if it does not fill then either the figure is not properly closed or else it is not all in one plane. curves can be created either by using lots of short edges together or by using the circle tool then deleting edges and replacing them with other shaped edges or by using the arc tool. 
to use the arc tool
first type in the number of edges you want your arc to consist of, then click on a point where you want one end of the arc to be, then click on a point for the second end of the arc. finally move the cursor to position the point where you want the arc to bulge to, you must check which axis you are moving this point along as it will determine what the orientation of your arc becomes. if the axis is correct then rather than clicking on a point type in the length you want to bulge by and press enter key.

these 2d shapes can be extruded(push-pulled)like any other. curved surfaces cannot be extruded, we will cover them later.

Step 5: Spheres and Cones

at first it would appear difficult to model a sphere or cone with sketchup but that is not the case. here is how:
for a sphere
first create a circle, then create a second circle with the same centre at 90 degrees to the original. divide this second circle in half along the middle so it looks like the image on this page. then select the edge of the full circle,click the extrude tool, use it to select the half circle's face and click. a sphere should be formed.

for a cone replace the half circle with a triangle, the whole principle here is similar to volumes of revolution where a 2d shape is rotated about an axis to form a cone/sphere/truncated cone/lightbulb shape/curved surface cone. just draw out half the cross section put a circle at 90 degrees to it on it's central line and extrude.

Step 6: A Quick Word About Pipework

pipes can be formed by the following method

first create a circle with the radius you want for your pipe, then divide the circle in half, draw a line out from the circle from the centre point of the line you just drew. continue this line long the route you wish the pipe to take using curves as necessary where you want the pipe to bend. now delete the lines used to halve the circle but not the line running out from the circle's centre, finally select the whole route out from the circle's centre then change to the extrude(follow me) tool and click on the circle.

Step 7: Modelling From Triangles

sometimes there will be no obvious way in which a shape can be formed with any of the previously explained techniques, when this is the case you will have to model it face by face. often you can use curves along different axes and join them up with lines to form the surface. once the surface(or any other you wish to smooth)is modelled select all the faces then go to "edit-->x faces-->select-->bounding edges"  this selects all the edges between the faces. then go back to "edit-->x entities-->smooth-soften edges"  . select the tick box on the pop up for soften coplanar and then the other tick box, then slide the slider along until you see all the blue selected lines between individual faces turn dotted. close the smooth-soften box and deselect. this now gives you a curved surface.

Step 8: Groups and Components

once you have created parts in a model that you wish to copy or move around/rotate(covered later) you select the faces/lines making up the object and go to "edit-->make group" . a blue box appears around the object after which it can be  shifted around without warping other geometry, in some cases it may refuse to move on certain axes, in this case you must go to "edit-->group-->unglue" which will allow it to be moved pr rotated freely. glued groups can be useful when you want to place text or a flat piece of geometry onto a surface as a label or sign, they also can cause problems to new users of sketchup. when you have a group or component you can click "edit-->group/component-->edit group/component". this allows you to modify the stuff inside it, when editing a component all of the instances of that component in the model will be altered accordingly, leaving the group/component is done by "edit-->close group/component". if you want to avoid the other components of the same type being changed when one is modified you should click "edit-->component-->make unique". you can colour  the surfaces in a group by just using the material tool to click on the group. if you want to get already made objects into or out of existing components you will need to copy them with "edit-->copy" then open the group, or close it to leave it and click "edit-->paste in place".

there is also a tab called the component window accessed by going to "window-->components". this can be used to search the 3d warehouse for components to add to the model, or to alter some basic properties of components. but by far the most important use of it is to click the home icon to see what components are in the model and then go to "(right arrow symbol)-->purge unused". this removes unused components form the model and reduces the file size. very helpful when you have finished a model and wish to upload it to the 3d warehouse.

a quick few WARNINGs: firstly when in the component browser(especially when using the home button) set the view to "list" this makes it much less likely to crash sketchup. secondly when downloading a component from the warehouse do not try and claim it is yours unless you really did model it. uploading someone else's model as your own(or without crediting them for it as a part) will get you the bad reputation you would deserve for such actions.

Step 9: Move Tool

once you have a group you are likely to want to position it, or copies of it elsewhere. select the group, first ensuring it is unglued from any faces it touches. use the move tool and click on one vertex, then click the move tool on the another vertex at the position you want the original vertex to move to. the move tool can also be used on lines or faces or vertices that are not in groups, when using it this way it will warp the geometry around it it often helps to press the "alt" key just after you have clicked on the vertex at the start. the move tool can also operate along a line, select the object you want to move, hover the object so there is a green,blue or red(the colour indicates which axis is used) dotted line between it and where it is being moved from. then either press "shift" and select a point at the distance you want along that axis or type in a number and press "enter". using "ctrl" will move a copy of the object, after clicking the position for the copy you can press "x" and type in a number to create an array or "/" and a number to create an array where the distance between the original and the copy is occupied by a number of copies. 
the "alt" key provides autofold function so an be used for example to create a cone with the end cut of via this method
first create a circle, next use the offset tool(will cover soon) to create a smaller concentric circle inside it. then select the inner circle's face, click the move tool and after you start to move it press "alt", then position it along the axis perpendicular to the circle's radius.

Step 10: Rotate Tool

another critical tool when manipulating objects is the rotate tool. here is how to use it
1. select the object you want to turn
2. click the rotate tool and align the disc shown with the plane you want to rotate in, this can be one of the axes or a face in the model
3. click on a point where you want to rotate about
4. type in the number of degrees you wish to rotate by making sure the object is turning in the right direction, or click on another point you want to snap it to

"ctrl" key can be used to copy, then "x(a number)" or "/(a number)" will allow arrays to be created, respectively all separated by the angle you rotated by or rotated so they each have an equal portion of the angle you input.

Step 11: Offset Tool

simple to use and quite useful the offset tool is an element of sketchup that might not seem to have much use at first, it does though. simply select a face, click the offset tool and use it to create a new face inside or outside the original in a concentric pattern. unfortunately sometimes the offset tool produces internal shapes rather different from the shape you wanted to shrink so sometimes it is necessary to go over the edges of these shapes with the line tool and delete parts of them.

Step 12: Scale Tool

sometimes a part is too big or small compared to the rest of the model, that is where the scale tool comes in. selecting an object then clicking the scale tool brings up a box around the object, you can click and drag on the yellow corner/edge/face boxes to stretch or shrink the object. "ctrl" will allow you to scale about the centre of the object rather than the opposite point, "shift" will scale the object by the same amount on all axes regardless of which box you move, this can be useful for resizing an object so that on one axis it's ends match up with positions of other geometry but the object is not changed in proportion.

Step 13: Intersections

intersect is useful where you have overlapping complex shapes but you want to make them into one outer shell. it can also help with cutting holes in a curved surface. the process is simple, just select  the objects/faces you wish to intersect then go to "edit-->intersect faces-->intersect with model/selection/context" . intersecting with model will mean a line is created across all faces that the selected object intersects with, intersecting with selection means lines are only added where selected objects intersect each other and intersecting with context means an object is only intersected with things inside it's group/component and not things outside that group. after intersection different faces can be deleted to give various new shapes. if the object you have selected is a group or component then the lines created will be outside of it so it's faces will not be cut.

Step 14: Materials

NOTE: material is applied as one continous texture to any individual face. if you want more than 1 material on the same face then you need to divide the face into separate parts.

materials in sketchup allow you to colour surfaces and add textures to them. at it's simplest level this merely involves clicking the paint bucket tool and selecting a colour or textured material from the lists then clicking on faces to apply the material, if you want to alter the positions/orientations of textures i describe this in the next step.  but there are also many other options. for example any material can be edited by changing it's colour, this is done by clicking the edit tab on the materials window then moving sliders or typing in values. i advise that for easy editing of colours you should select the HSL method  which gives you separate sliders for hue(what frequency of light it corresponds to(i thought that was the best way to describe it despite differences between light and colour) ), shade(how grey you want it from grey to bold colour) and lightness(how dark from black to white). there is also a slider further down for opacity which can go from 0(utterly transparent) to 100 (utterly opaque). there are also buttons that allow you to match the colour of a face already in the model and the colour seen at a particular point on your screen. just click one of them then click on the face/colour you want to copy. other useful tools in the materials window include the home icon which lets you see only the materials that occur in your model. there is a purge unused tool that lets you remove materials that no longer occur anywhere in the model(though components containing the material in question must first be purged themselves in the component window).
there is a sample paint tool(dropper icon) that lets you click on any surface in the model and select the material applied to it, clicking on another face afterwards applies the same material to it. there is a tab for making a new material that lets you (surprise,surprise) create a new material and set all the properties(including a texture) for it in much the same way as you can alter properties of existing materials. lastly i should mention that when you want to alter a material slightly but leave the original material elsewhere in the model it can be helpful to change the name of a material in the bar at the top of the window, also important when importing parts from other models with the same named material but differently coloured/textured to the material in the model already with that same name. to paint multiple faces the same colour at once select them all then click on one of them with the painting tool as you would paint an individual face and they will all have the same material placed on them.

Step 15: Adding a Texture

textures can really add to the realism of a model. i know many great models that look excellent in renders despite extremely basic and simple geometry because of the textures applied to them. texturing in sketchup is not the same as in other 3d applications and it is quite hard to achieve some of the possible texture effects(bump mapping, overlayed textures,etc) without some very hard work in blender after conversion, it can still be effective though. also texturing in sketchup rarely works to form a single image wrapped across the whole surface but instead each face having an image individually positioned on it. this is one of the things that you may not learn in most sketchup  beginner tutorials, but it can do some really great things. the "add photo texture" option is not covered here as it is heavily reliant on google earth and the techniques used here can produce the same effect.

changing a texture
some materials come with a texture on them, this texture can however be changed at any point to something more appropriate for whatever surface it is on. it can also be resized.
the "browse" button(blue arrow coming out of folder icon) can be used to find a texture. just click then a file browser pops up and you can search your computer for saved image files to use as the texture, if a texture will be repeated across the same surface it is advised to make it seamless, this can be done in the image editing software GIMP.
the "edit texture in external image editor" button(orange arrow coming out of a chest of drawers icon) opens the image in a program such as paint or GIMP, but you must set which external editor to use by the following method. 
under "window-->preferences-->applications-->default image editor" there is a search box where you must find the .exe file of the image editor you want to use. on windows xp paint is usually found under C:\WINDOWS\system32\mspaint.exe  .
below the box displaying the name of the texture image are 2 boxes with lengths in them, these values can be changed to scale the size of each rectangle of texture. the "lock/unlock aspect ratio" button (a curved bracket next to a chain link icon) must be set to unlocked if you want to scale the different lengths independently.
if you want to add a texture to a material that was previously untextured then you need to tick the check box "use texture image".

positioning a texture
this is done per face where a texture is used, on curved surfaces you must use the smooth-soften tool to make them fully unsoftened(they can be resoftened after the texture has been positioned). click on "edit-->face-->texture-->position", four coloured pins now appear and some blue dotted lines are visible along the edges of each rectangle of texture, the texture will extend beyond the face and will appear semi transparent whilst in this mode. using any tool, including those that change viewing position or angle, will cause the program to leave the position texture mode and go back to ordinary view. here is a summary ofthe pin's functions.
1. yellow pin, this is use to distort the texture, it has some unusual effects on the image and will rotate it about axes that are not one the plane of the face. it can be used to make an image taken ,for example when looking up at the face of a building stretch so it appears to be taken face on.
2.green pin, this is used to rotate a texture. after clicking it a protractor appears, moving the pin around while holding down the left mouse button will let you rotate about the centre of the protractor or scale about that point. it is highly useful.
3.red pin, this is a very simple tool. click and hold to move the image across the surface  and change the position on the plane of the face. again very useful.
4. blue pin, this also scales the texture but only about the axis defined between it and the protractor centre based on the red pin. the blue pin can also distort the texture in other ways.

after setting the texture correctly click the select tool, the position texture mode will close but the texture on that face will now be as you positioned it.
"edit-->face-->texture-->reset position" will let you return the texture to how it was before you made these modifications.
as a note you CAN zoom out or in but only by using the scroll wheel on the mouse.

other stuff to know about texturing
for ease of export textures should be positioned on the forward side of each face, only this side is preserved upon export, the rear side is lost and so is any mapping used on it.

if the texture used is a .png with transparent parts then those transparent regions will be clear in the model.

Step 16: Preparing for Export Towards Blender

from this step until the step about basic animation in blender the instructions are based on exactly what i did to export my phoenix class hyperspace fighter(it is shown in some images earlier in this instructable) model to blender and to begin animating it, there may be some details that may not work for other specific models but if you describe any problems you have i will be happy to see if i can work out what you should do. also there are a few other techniques involved in certain stages if you have models with more complex moving parts for example, i will only cover the absolute basics of these. the following screen shots are taken during an actual export and not just shown as examples.

if we want to do some truly amazing rendering and animation with sketchup then we need to export to a more complex 3d program. blender is the free program that can be used for this sort of work, 3ds max, c4d, lightwave and many others may also work and should have no trouble importing the obj file that is produced part way along the route from sketchup to blender. the process described here for blender will apply in the same way(i think) until the step where we open blender and import the obj file. for other programs you will need to use their own importers to bring in that obj file and then complete the equivalent process for rearranging them into the full model and making any necessary material modifications.

the first stage of preparing for export is to ensure that all faces have the same material on both sides, if this is not done then the material on the "backside" of the face is lost upon export. you can check which is the front and rear sides by going to "view-->face style-->monochrome", all the faces will turn blue or white in colour, do not worry the textures and materials are not lost(they reappear when you switch back to"view-->face style-->shaded with textures"). where you see blue faces on the outer surface of your model you must flip them by selecting then using "edit-->face-->reverse faces" so they become white/grey. any positoning of textures must be redone on the white side of the face after the flipping by using the same method covered on the texturing page of this instructable.

another crucial element is separating out groups that you want to be separate in the blender model. export from sketchup destroys the group hierarchy so if an object is supposed to move/rotate independently of the rest of the model it needs to be moved away from the rest of the model so it is easier to regroup in blender. it is best to use the move tool to move it along an axis such as red,green or blue by a "clean" distance such as 1.00 metres, 5.00 metres or 10.00 metres. in any case make sure you move the object along an axis and remember EXACTLY how far you moved it, which is why a "clean number" is best. also separated objects must NOT intersect with other objects and must be outside of the model so they can easily be selected in blender later on. this is another reason that using sketchup in metres is helpful, i have never tried this using feet but it may complicate matters when you try to reorganise in blender.

also you can speed up export by removing excess geometry by deleting it, alternatively if an object appears(without being scaled differently) a number of times than delete all but one of them then, once in blender, it can be copied and the copies put into the positions where the others were. this can be difficult if the separation is not a whole number, though if a vertex on each copy of the object is attached to another vertex in the rest of the model the snap tool can be used to position the copies.

finally i should mention that when a material has no texture it MAY(but is not always) necessary to texture it using a plain jpeg image(it need only be a tiny white square). although this turns the materials white you then go to any of the sliders affecting the colour and move them up by one, then down by one and the original colour is restored.

now we are ready for export!

all my notes on export have been sourced from my tutorial on sketchup export, i have tried to clarify anything that may be confusing and have added extra detail on certain matters. the following pages are partially copied from my tutorial so do not be surprised if  you recognise some of the text.

Step 17: Exporting Part 1

here goes the first part of exporting, this gets the model with textures out of sketchup and into a format called .xml . xml is not importable by blender but it can be converted to obj which blender will import, that is in the next step.

Be warned this doesn't necessarily work on newer versions of sketchup(those after 8), i have not tested those newer versions myself so cannot be sure either way whether this functions properly any more. It works perfectly with version 8 of you can find that version of sketchup available for download anywhere.

1. download this plugin for sketchup
http://www.kerkythea.net/joomla/index.php?option=... follow the simple instructions on that page and in the txt file inside the zip you download. just copy the folder and the rb file into the sketchup plugins directory, unfortunately kerkythea's site appears to be down at the time i published this instructable so if you really need the plugin i may be able send you a copy.

2.now open sketchup a small pop up box should have appeared with some brightly coloured buttons, do not press any of them yet.

3. then open the sketchup file you want to convert in sketchup, the new toolbar should still be visible.

4.now press the first button on the new toolbar marked "export model to kerkythea"

5.select the options as shown below

geometry "yes"
lights "no"
clay "no"
photomatched "no"
default uvs "yes"
instanced "no"
(there may also be an option about exporting slection only, set this to "no")

6.click "ok" then give the file a name

7.click "save" then wait

8.on the box that now pops up click "yes"

9.then a file browser labelled "LOCATE kerkythea program , PLEASE" appears, click "cancel"
after clicking cancel close sketchup, provided you saved before clicking "export model to kerkythea", clcik the "no" button for if you want to save changes.

10.now we have the file in kerkythea format here comes the next step

11. find the file using my documents and copy the xml document into the folder where the textures of your model have been saved(that folder will be in the same folder asthe xml file and named TX_(file name of xml)

now continue to the next page to find instructions for converting the .xml file produced by the sketchup exporter to an obj that blender will import.

Step 18: Exporting Part 2

now to convert xml to obj

12. find the file using "my documents" and copy the xml document into the folder where the textures of your model have been saved(that folder will be in the same folder as the xml file and named TX_(file name of xml)

13. download this file http://www.nicetuna.com/kt2objVITAL NOTE: this version of the converter batch file only works if you have java installed on your system. i found this the hard way when after removing java thinking i did not need it the converter would not work until i reinstalled java. java can be found at http://www.java.com/en/

13.5. There is also a .NET version of the file which can work without the need for java to be on your system, the .NET version can be downloaded from the same page as the java version and it's .bat file is simply titled kt2obj. I found this to work on my windows 8 pc without needing java on that machine, for a while i had java installed on the windows 8 machine but even with that the jkt2obj file would not function. I removed java and tried the .net version which worked perfectly on the windows 8 computer.

14.extract the .zip file into a new folder

15.open a file browser and go to where you left the xml file

16. right click and copy it

17.go to the folder where you extracted the zip file to and select the file "jkt2obj" it is an MS-DOS batch file

18. right click then paste the .xml file onto the ms-dos batch file named jkt2obj

19.click run on the pop up window (scan for viruses first if you wish)

20. wait until the command prompt window displays "press any key to continue"

21.press a key then open up the folder containing the old xml file, an obj and mtl file will have appeared in that folder

22.open blender, right click on the cube in the field of view and press delete key to delete the cube.

23. import the new obj file using "file-->import-->wavefront(obj)", then browse for the model. leave the import options on the default settings. these are as follows

"operator presets"
smooth groups(yes)
split by: object(yes), group(yes)
clamp size= 0.00
forward "-Z forward"
up "Y up"
image search (yes).

the next page describes the process used in blender to reorganise the model ready for animation.

Step 19: Importing Into Blender

now we cover importing into blender but first you will need to be able to atleast move your viewpoint around in blender and perform basic editing of objects.
key codes you will need to learn are
"middle mouse button(scroll wheel)" should be clicked and dragged to orbit

"middle mouse button(scroll wheel)" should be clicked and drag whilst "shift" is held down to pan

"middle mouse button (scroll wheel)" should be scrolled to zoom in and out

"ctrl"+"alt"+"numpad 0" will bring the rendering camera to you current viewing angle

"numpad 0" will change your viewing angle so you are looking through the rendering camera

"ctrl"+"p" will allow you to parent objects to one another, this is blender's equivalent of groups. selected objects are parented to the active selected object.

"right click" will select objects, right clicking on an already selected object usually deselects it. objects with dark orange rims are selected, objects with yellowy orange rims are actively selected.

in blender as a standard you can see four regions upon opening and clicking o hide the pop up splash screen, these are:
the 3d view window(centre displaying 3d objects)
the timeline(bottom showing a green line and a sequence of numbers along a line)
the outliner(top right displaying drop down list of objects in the model)
the properties window(bottom right, this can display all sorts of different properties of the selected objects including name and materials. it also shows render options.

to delete an object in the 3d view select it and press "delete" then confirm deleting on the pop up that appears.
to move objects in the 3d view around select then press "g" followed by the axis you want to move on "x,y,z" and type in a length then hit "enter". movement on a local axis(explained later) is done by pressing the axis key twice, so the local x axis is "g" "x" "x" then a number and "enter". the number is in metres.

to rotate objects in the 3d view(usually about their origins which will be explained later) press "r" followed by the axis you want to rotate about "x,y,z" then type in an angle in degrees and hit "enter". the same applies for local axes "r" "y" "y" to rotate around local y.

to scale objects select and hit "s" then the axis you want to scale about"x,y,z"or no axis if you want to scale equally on all axes. the local axis method of pressing the axis key twice also works here.

to join objects into one select them and go to the object tools side panel on the left, click on "join". the active object must be selected and the objects being joined will take on it's name.

the origin option under the object tools side panel can be useful for setting origins by using "origin to 3d cursor". the 3d cursor can be positioned with a left click from the mouse or with "object-->snap-->cursor to selected".

there is a tool bar at the bottom where "view-->" "select-->" and "object-->" options are visible. the white circle options box lets you switch between viewing modes of textured, plain solid shading, wireframe and bounding box. the options box showing a brown cube and the text"object mode" should be in object mode until you need to toggle into edit mode to edit and select individual geometry, faces and lines.

"view-->align view-->view selected" can help you navigate in the same way as zoom to extents of an object did in sketchup.

selecting an object then pressing "h" hides it, "alt" +"h" will unhide all hidden objects in the scene and select them.  this works exactly the same when in edit mode.

"b" is used to select all the objects visible within a box you draw on the screen. press "b" click where you want to start drawing the box then drag to set the opposite corner.

if you have any trouble with this search for blender basics tutorials on google or comment here/PM me for help.
http://wiki.blender.org/index.php/Doc:2.6/Manual  may help with key combinations and methods but it can be very confusing to a new user and it is still not very easy to follow even for me.


immediately after import save the blender file inside the "TX-(sketchup model name)" folder. this is so blender can locate the textures.

23.after importing the obj file it should look exactly the same shape as when you exported from  sketchup but it will probably be white in colour and may be rotated differently. select everything using "select-->(de)select all". if objects are already selected you will need to click this twice, once to deselect what is now selected and once to select everything.

24. now join all the objects in this mesh together into one, this is done with  whilst in 3d view mode with "select-->(de)select all" click on it a second time if it does not select everything. this should select all the parts of the obj file that was just imported and they will turn orange, right click on any other objects now to deselect them. finally when only the parts of the obj file are selected click "join" under the object tools panel on the left.( we shall be calling this main body object the parent object in this tutorial).
then proceed to go through the mesh in edit mode as follows

   25. select(using "b" key) an isolated object by drawing a box around it, make sure that the check box to select obscured from view objects is on and that there are no other objects directly behind what you select. it often helps to be in face select mode for this, click the button showing a grey box with an orange face to enter face select mode.

   26. press "p" key(then click on "selection" in the small pop up) to separate the selection from the main object then close edit mode and select the new object, give it an appropriate name(in this tutorial we shall be regarding it as the daughter object) and set the origin for it by positioning(often with the snap to tools) the origin. the origin is set by selecting the object then entering edit mode, once in edit mode right click to select a vertex where you want the origin positioned. to select vertices you need to set edit mode to select vertices by clicking the button showing a grey box with a yellow dot at it's corner. then to set the origin to that vertex use "mesh-->snap-->cursor to selected", after that toggle back to object mode and click "origin-->origin to 3d cursor" under the object tools tab.

   27. then move the newly separated daughter object along a certain distance on 1 axis back to where it belongs on the model, essentially reversing the separation process you performed while still in sketchup. if it has been moved by a less clear distance or along multiple axes you need to sue snapping to reposition it. first set the origin on the daughter object to be at a vertex which precisely lines up with a vertex on the parent object when the model is assembled properly, then open up the main body (parent)object in edit mode and select the vertex at the point the origin of the daughter object must go to. click "mesh-->snap-->cursor to selected" to set the cursor to this point in the parent object. return to object mode and select the daughter object you wish to move. click "object-->snap-->selection to cursor" which will move the daughter object so it's origin is in the same place as the cursor is.if an object needs copying because you deleted all but one copy of it in the sketchup file before export  then use the "duplicate objects" button in the left hand toolbar. immediately after pressing it press "esc" key to stop moving it, then it can be snapped or moved using "g" "r" and "s" into place. before the next stag(parenting) you should ensure all objects have the correct origin set and the correct position. this also means the parent object needs an origin, this can be set by the same method as setting origins for other parts or you can select the parent object, and click "origin-->origin to geometry" which sets the origin to the object's centre.

28. once this process is repeated for all parts of the model we must parent the parts back into some sort of grouping structure so when the parent main body object is moved the rest of the model follows it. select all the daughter objects first then select the parent object last, objects(such as the camera and lights) that are not supposed to be part of this grouping structure should not be selected. to parent press "ctrl"+"p" and choose object from the pop up list. for more complex groupings such as a battle ship with a gun turret where the turret can rotate while the gun barrels elevate and lower first parent the gun barrels to the turret then the turret to the ship. an object can have multiple children but only one parent. the grouping and parenting will be shown in the outliner window, parents will be shown and the small "+" icon next to them must be clicked to reveal a drop down list showing their children. 

29. smoothing once all parts are separated go into one of them in edit mode, select all and remove doubles using the remove doubles option on the left hand side toolbar. then return to object mode and click the shading"smooth" button, repeat for the other objects in the model. this makes the model appear curved rather than using flat faces, this step can be missed if you prefer flat faces but removing doubles still helps with reducing the file size.


to restore textures we must change the 3d viewer window to a properties window,this is done using the small box in the corner at the bottom left of the 3d viewer window and setting it to "properties". then click on the texture tab in that properties window to display information about the texture on whatever material you have selected in the properties window on the right.

first check all the textures are using the correct file, under the tab marked "image" in the texture panel find the text bar marked"source" it should be reading "//(texture file name).(file type)". if it is not click the file browser icon on the right of the bar and search for the right image. it should be in the "TX-(sketchup model name)" folder where you saved the blend file you are now working on, if it is not copy the right texture file into this folder using my documents then use blender to find the image and assign it to the material. if you are unsure where a material appears on the model and wish to check it is in the right place you can go into edit mode in a 3d view window and click the "select" button in the materials panel to select all faces bearing the material in question, if the texture and material have swapped for that on another set of surfaces the best option is to just use the textures in the correct places and ignore the names of the materials, if some of the texture is on faces it should be on but some is on faces where it did not occur in the sketchup model then it can be harder to solve(there are some tricks involving assigning different materials comment or PM me if you have these issues).

once you have checked that all textures are on the right surfaces and that every material has it's texture assigned in the form "//(texture file name).(file type)"(as seen from checking the texture panel of every different material) we can move onto some basic editing of materials,  in blender it is more complex than sketchup...

repeat the following for each material

in the "diffuse" panel click on the coloured(often white)  bar above the intensity bar, a colour wheel is shown, click the small paint dropper icon then immediately click on the preview image of the textured material to set the material colour. the intensity bar below can be slid up or down to make the material brighter or darker.

also set the colour under the "specular" tab, this is the colour you want to be shown where intense light reflects off the material, it is often best to use the materials own colour by clicking on the colour tab and using the paint dropper icon to click on the coloured bar of the diffuse tab above.  the slider here can be slid up to make the material shiny or down to make it dull, the colour used for the specular of very dark materials should be lighter than the diffuse colour for them, use the black to white slider under the colour wheel pop up to change this.

then decide if you want the material to glow, if so type a positive number into the "emit" bar under "shading".

when a material was transparent in sketchup you will probably want it to remain transparent in blender, the process for restoring transparency is.
1. set the alpha under material to 1.00
2. scroll down in the textures panel to see the "influence" tab
3. untick the bar marked "alpha"
4. return to the materials window and slide down the alpha that you previously set to 1.00 until the material is transparent enough.

repeat the steps in bold for each material.

the model is now ready for use in blender !!!

Step 20: Back From Blender

some features are available in blender, such as subdivision that sketchup lacks however this is not to say you cannot achieve those effects in sketchup. there is a simple method for converting blender files back so sketchup can open them. please note some texture effects, glow, all animation and all lighting will be lost when opening a model in sketchup. this can also be very useful for importing models to sketchup of types sketchup cannot import by itself, it allows you to use a multistage process to get an obj file(very common on 3d model download sites due to the widespread use and universality of obj models) into sketchup via blender for example. there can be some problems with this but it usually works very well and i blame any inaccuracies in the obj files i imported to sketchup via blender and this method upon slight errors in the original obj meshes before i imported them.

the process is very simple

1. separate out parts the same way as you did for exporting from sketchup to blender, blender's object and grouping structures will not be imported to sketchup.
2.then go to "file-->export-->collada(default)(.dae)"
3. ensure it will be saved to the same folder as the blender file is currently in
4.tick the options of "apply modifiers", "include UV textures", "include material textures", "copy" and "use object instances".
5. click export and wait.
6. once this is done open sketchup
7.in sketchup go to "file-->import..."
8.in the "files of type" bar at the bottom of the file browser that appears select "Google Earth/COLLADA Files(*.kmz,  *.dae)"
9.click on options bar at the left and tick for "validate COLLADA file" and for "merge coplanar faces"
10.browse to where you saved the dae file, it should be where the blend file is saved
11.click "open" and wait, this can take ages
12. the blender model is now in sketchup however it is no longer animated, no longer has glow effects and has no grouping structure. it may appear as one component, you will need to use the smooth/soften tool to make it appear more like it was in blender by hiding all the lines making up the curves.

blender can also export obj which is useful for transferring to most 3d programs
1. select all the objects but not the lights or camera
2.in blender go to "file-->export-->wavefront(.obj)"
3.tick the following options: "selection only","apply modifiers",  "include edges", "include UVs", "write materials",  "objects as obj objects", objects as obj groups". set scale to 1.00, forward to "-z forward", up to "Y up", path mode to "auto".
4.ensure object is exporting to same folder as blend file is currently in 
5.click "export OBJ"

note: for most obj exports separating objects is not necessary as obj files and most of the programs you import them into will support objects in the same way blender does, origins of objects will however be lost. these will need reassigning in another 3d program. if the program you are importing to does not distinguish between the objects itself then separate as usual.

in both the processes above ensure that you rename the file before export if there is already a file of the same type with the same name in the folder with the blend file.

Step 21: VERY BASIC Animation in Blender

as a quick note i advise copying the folder which contains the blend file and all your textures to elsewhere in your documents now, this way we can work on a separate file to animate whilst leaving an unanimated model for copying into any other project you want to animate.

the key concept to understand when animating is keyframes. what most 3d (or even 2d) animation programs do is get you to set points in time at which an object is in a certain position/rotation/scale then get you to set another similar point(these are the keyframes). when you play/render the animation the software fills in the "gaps" and works out what everything should be doing in the frames between the two key frames. in blender many things, in fact almost everything, can be keyframed. this includes positions of geometry, rotations, scales, colours, luminosities ,and even(using some complex modifiers) parenting. on this page i will introduce you to basic animation and basic rendering(i will not explain all the details of it and the possible options, but i will show you a method that always works effectively for me),  will cover making keyframes, "camera" use and quick renders. i start with a list of how settings should be for fast but high quality rendering.

settings for rendering animation

go into properties window

under the world tab set as follows
leave "world" as it is
leave "ambient occlusion" unchecked
turn on "environment lighting" colour should be "white" but "energy" can be set as best fits your scene
leave "indirect lighting" turned off
set "gather" to "raytrace", attenuation should be "distance:10.000", sampling should be "constant QMC", samples should be "5", leave "fall of" turned off.
leave "mist" and "stars" turned off
do not add any "custom properties"

then under the render tab
under "render" do not click any of the boxes yet, set "display" as "image editor"
leave "layers" as standard.
under "dimensions" choose "TV PAL 4:3", "resolution" and "aspect ratio" should remain unchanged. if you want a different aspect ratio then set x and y under the "aspect ratio" panel to "12.000" and alter the "x" and "y" sizes under "resolution". set "frame rate" to custom then type in "15", leave the box below unchanged. do not turn on "border" or "crop". leave "time remapping" unchanged.
under "anti-aliasing" click "5" for the value, leave the other fields as "mitchell-netravali", "full sample" turned off and size as "1.000".
leave "sampled motion blur" turned off.
under "shading" turn ON "textures", "shadows" and "environment map". turn OFF "subsurface scattering" and "ray tracing". set "alpha" to "sky".
leave "performance", "post processing" and "stamp" as standard.
under "output"set the file path to where you want the file saved to, turn ON "overwrite" and "file extensions". leave "place holders" OFF. change the "png" format to "avi raw". click the "RGB" box.
do not change the settings under "bake".

you will probably need to rest all of this just before clicking render, also ensure that the folder where the rendered video will be sent contains no video files that could be overwritten, if it does move those videos for now. often after closing and reopening a blender project the "dimensions" settings under the render tab will alter back to the default, make sure "TV PAL 4:3" is selected from the drop down list, then change aspect ratios, resolutions and frame rates afterwards. when you want to render the final video click "render as animation" immediately after resetting the dimensions settings.

camera settings

select your camera object in the 3d viewer and go to the properties window, a new tab showing a film camera icon should be visible. click on the icon to enter the camera tab. leave the lens as "perspective", and the focal length at 35.000 millimetres(this can be changed for zooming in and out effects while the camera remains in the same spot). under "clipping" set start to a very low number(perhaps 0.01) and end to a very high number(in the tens or hundreds of thousands). leave the other options below as default.

with those settings selected we must  light  and animate before we can render.

at it's most basic lighting just involves placing a sun "add-->lamp-->sun" above the very highest point in your scene and below the very lowest point. of course by adding extra lights you can create more interesting effects. maybe have a very dim light from below so it only appears as if  the sun above is providing light, or add spotlights to make searchlights or illuminate certain details, i find it often helps to place spot lights at the intakes of engines so the details inside are still visible.  the settings for suns and other lamps can be altered in the light tab of properties when they are selected. unless really need them it is best to set the shadow for these spotlights to "no shadow" and set blend to 0. when rendering it is essential that some lights are present otherwise the entire render will be dark with only the emitting objects visible.

to animate first set a position and rotation(maybe also a scale if the object shrinks and grows during the animation), press "i" key then click  "LocRotScale"  then move along the timeline in the bottom window using the slider. at a later point in time on the timeline reposition/rotate/scale the object and press "i" and click "LocRotScale" again. when you play the animation using the play icon on the timeline you will see the object move between the keyframes.  you set the start and end points of a motion, blender fills in the bits inbetween. yellow lines vertically on the timeline indicate keyframes for a selected object, the green slider indicates which point in time you are viewing at. keyframing can also be done for numerical values in the properties window, right click on the box where the number is typed and click "insert keyframe" to set a keyframe for intensity, colour, emit,transparency, or position,rotation and scale(found under the object tab). if a box is yellow in colour it means you are at a keyframe for that value, if it is green it means the value is keyframed but you are not at a keyframe for it on the timeline. all objects, including meshes, lights and camera can be keyframed. to remove a keyframe move the slider on the timeline to that point in time, change the timeline view to "dopesheet". then find the object for which that keyframe is applied, scroll down to that object on the up-down axis of the dopesheet and find the keyframe on the left-right axis. right click the keyframe and press"delete" to remove the keyframe. to replace a keyframe go to that point on the timeline move the object that the keyframe applies to to another position then click "i" "locrotscale" to put another keyframe over it and replace the old one.

animating the camera
the camera is animated in the same way as objects, when animating it often helps to press "ctrl"+"alt" +"numpad0" to put the camera into your current viewing position. then you can animate by giving it a keyframe now and then a keyframe at a later time when it is in another position. it can be moved to another position by using "ctrl"+"alt" +"numpad0" from another angle, this however can result in unusual paths taken by the camera between the positions. it can alternatively be animated by moving the camera whilst looking through it "numpad0", then select the camera object and press "r" to rotate it or "G" to move it. most common camera movements from films can be replicated using just "g""z""z"  ,  "r""z"  and "r""x""x"  .

lens flare
a lens flare effect is great fro adding realism to your scenes(or absolutely necessary if you are an aspiring JJ abrams , lol), irt can also help emphasize how bright some parts of the scene are. the following procedure allows for a basic lens flare effect on your renders. the attached images probably demonstrate this best.

1. open the "node editor" in place of the 3d view window
2.click the "compositing nodes" box, and tick "use nodes"
3. you should now see two boxes labelled "render layers" and "composite"
4.click "add-->filter-->glare"
5. a new box now appears marked "glare"
6.change the settings of this glare box to:
fog glow
threshold: 0.500(raise or lower to change minimum brightness needed for a glare to appear)
size: 8

7.select and move the glare box until it is directly over the "wire" connecting "render layers" to "composite", the wire should turn orange and the small circles on either end of the glare box will be yellow.
8. release it and drop it onto the wire, the wire is now cut so it has a wire from "render layers" into "glare" and another wire from "glare" into "composite".
9. add another glare filter between the first one and the composite box.
10. set this new glare filter to:
iterations: 2
colour modu: 0.000
mix: 0.000
threshold: 1.000
angle offset: 0
fade: 0.750

11. press "f12" to render and check it looks good, if it does not you can change quantities in the glare filters to produce different effects but i find these described here to be best. to make flares bigger or smaller you should make the glowing objects in the scene brighter or darker.

the importance of "f12"
the "f12" key is extremely useful in checking if a video is going to come out correctly. although you can watch the events with the play function on the timeline that does not let you see what the actual image will look like. pressing "f12" will bring up a render window in place of the 3d viewer, over the course of 10 seconds to 5 minutes an image ill be produced. this is the image you will see in the final video at that point on the timeline. you can zoom into the image with the scroll wheel and move around it to examine details by clicking and dragging with the middle mouse button.

a trick for space scenes
a useful trick for a space scene: if you want to animate a ship involving spacecraft the following information could be very helpful.
set the cursor to the centre(  "object-->snap-->cursor to centre"  )add a UV sphere(  "add-->mesh-->UV sphere"  ) and scale it up hundreds of times( select the uv sphere then press "s" key followed by typing in "800"(or another large number).). then in the materials tab of the properties window click "new" set specular to zero and diffuse to black. go to the texture tab, click "new" change it from "clouds" to "image or movie" then open a seamless image texture of space (this can be produced by  importing an image of space to GIMP and clicking the make seamless option). set the mapping projection to sphere. then turn up the materials emit value to 1 or so. it is essential to add a sun light  "add-->lamp-->sun" at the very top and bottom vertex of the giant uv sphere, the sun's settings can be left as their defaults unless you want to darken or brighten everything overall. the texture used for the space background must be a very high resolution image or it will appear very pixelated when expanded to cover the sphere.

once you think the animation is complete, check and recheck all the settings including:
render settings, output settings, world settings, camera settings...
then try a few "f12" renders to check that the individual frames look ok at key points.
then click the button under render saying animation.  you will know when rendering has finished because the green line on thew timeline will move back to wherever you had it before you started to render and a piece of text saying "Time: xx.xx.xx " will appear at the top of the render window. the rendered image will no longer change and will remain the same one. once rendering has finished go to the folder where you sent the video to and it should play, if it does not this may be because the settings were wrong fro rendering. an example video is shown below.

p.s. if you are interested in how i made the engine flames, the camera following the ship or any other animated effect please PM me and i will add instructions on that. i am also happy to help with any problems you have with this stuff.

Step 22: Tips for 3d Printable Models

3d printable models must be:
.stl files (this can be easily exported from blender but there is also a sketchup exporter for it available somewhere online).

it must be a watertight solid object, so it needs an outer shell with no holes. in sketchup you can guarantee a solid model by modelling from a box which you have saved as a group. it will be labelled as a "solid group" under "edit-->", then draw in lines to it's faces and extrude them or use move tools on the vertexes. you will know it is printable if after shaping what started as a box it is still labelled as a "solid group". delete stray edges, delete internal faces.

there can be no faces extending away from the model that have no thickness, all planes must be part of a solid shell.

if parts are supposed to be able to move independently of each other on the printed model then check what spacing is needed in the file, this will vary for different printer types.

check what level of details the printer can produce, what accuracy it has. anything smaller than this may not be printed.

surfaces are no longer all that important, what matters are walls. walls should generally be atleast 0.5 mm thick.

no open holes.

edges cannot be shared by more than 2 faces.

normals should all point in same direction(outwards). in sketchup normals refer to the white side of a face.

large objects can be hollowed but be careful to ensure the object still has thick enough walls and is still a solid shell.

make sure the model fits inside the maximum volume the printer can output, scale down models if necessary. objects with working parts with a size that matters should be modelled after knowing how big the printing space is.

gaps must be left between moving parts, atleast 0.5 mm.

it is going to be a real object so do not ignore the laws of physics, they may not apply on the computer but they will to the object. narrow parts bearing weight should be thickened, model should be stable in the way it is suppose to stand.

bipedal figures should always be balanced on atleast two points, or more if possible. if you wish to raise a leg then have them standing with that foot on another object.

in sketchup it can help to scale up for modelling then scale back down for printing.

in sketchup it can help to use a larger number of segments for curves and circles if you want a smoother printed shape.

all edges must be shared by exactly 2 faces

there must be no duplicate surfaces, this means faces in the same place, they will exhibit z fighting when viewed in sketchup and will flash between having the colour of each of the materials of the faces occupying that space. in sketchup z fighting is usually due to a face in a group overlapping with a face outside the group. delete one of the faces that overlap.

for obvious reasons an object cannot be floating in mid air above the rest of the model.

as i final note i should say that the best option for making a model printable is to model it in sketchup first then save the model as a group and create another group sharing the same outer surfaces as the original model. this group should be labelled as a solid group when selected from outside, if it is you know that the group is printable. all white sides to faces should point outwards in the group you wish to print.

the images on this step show examples of what manifold, watertight and hole mean in this context. i have also shown some images of preparing a sketchup model that was not printable to form a printable file. this is exported using the kerkythea then obj into blender method. in blender i open the imported obj in edit mode and click "select-->(de)select all" until every face in the model is selected then i click "remove doubles" in the "mesh tools" side bar on the left. after this i export as a .stl then upload it to http://www.netfabb.com/cloud/ which will check it some more to ensure it is printable.

another useful service is http://willit3dprint.com/  thias checks your files for use with specific types of printer. if it says there are problems with a model it will highlight where and you can modify the stl file before re-uploading it to willit3dprint and checking again.

Step 23: Sources of Free 3d Models Online

below is a list of links to 3d model download sites, all are free those in the bottom list require registration by email before downloading is possible. i warn you now that some models may be of low quality and others may be in formats that are hard/impossible to import. .max and .lwo are well worth avoiding.

totally free
http://sketchup.google.com/3dwarehouse/  (one of the best but only supplies .skp models)
http://www.blender-models.com/model-downloads/  (this seems to have some problems and sometimes a proxy may be required to access it if it tries to lock you out with captchas)
http://sketchup.google.com/3dwarehouse/search?uq=0371774692060490075941444&scoring=m  (some of my models, you cannot use them in anything without my permission but feel free to learn from ho they were constructed)

register for access(no personal details needed)

http://www.3dvia.com/search/  (many high quality on here, you can view in 3d online. not all can be downloaded)
http://www.foundation3d.com/index.php?categoryid=38&p13_sectionid=91 (great models but most are .lwo, these lose textures on blender import on the few occasions it works.)

you should note that the models should not be used in anything without crediting the author and linking to the download page, also respect the wishes of the modeller when using his model and use only as he permits.

Step 24: Thank You for Reading This

thanks for reading this instructable, i hope it helps and inspires you to begin 3d modelling or animation. it really is one of the most enjoyable things you can do on your computer and once you know how the 3d models can be put to many uses, rendering, animating, 3d printing, substituting into other places, creating visual effects are just some of the possibilities. contact me for any further advice on these matters. thanks, please vote for this instructable.

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More by resistanceisfutileiflessthan1ohm:Sketchup 3D modelling, file conversion and advice for 3d printing, a short guide Converting From Sketchup to Blender Remote controlled Electric shock "present" 
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