Today I am going to show how to use Blender to color a 3D model and print it in color using the sandstone material.
This video is not going to be about building the model just about hot to paint it and get it ready to print.
I am going to give you a blender file with skull I am working on however it will be blank. It will be up to you to color it and and scale it to print it at the size you want.
Now something of note; I don't own a 3D printer but I print my models using a company called Shapeways and using their sandstone material. So if you own a 3D printer and or another kind of material that prints in color I can not guarantee this will work. However since the color on the model is all just data I don't see why this wouldn't work ells were.
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Step 1: Got Skull? No. Well Here You Go ' )
Why are we using a skull? Well folks It's a project I am doing for a friend, this was a hard model to build and I figured I should share it with you and save you some of agony in building it your self.
A few notes about the model. It comes in four parts. The top part of the head, the jaw and the top an bottom rows of teeth.
The teeth have a hole in the head and jaw behind each tooth so if you delete a the faces for that tooth it, it will have a cavity. Just NOTE: the teach along with each part has a multi res modifier and a mirror modifier behind it which you will have to apply first unless you want your skull to have symmetric missing teeth.
Applying these modifiers will come later on in this tutorial so just read on and you will see why.
Step 2: Cycles Render or Blender Render?
OK there are two ways you add vertex color to a model in Blender. You can do it in Cycles rendering or Blender's default rendering. I like doing everything in cycles rendering so I will show this off first and then Blender rendering so when you read this just skip on down to the proper heading of which interest you more.
The skinny Cycles is a little more complicated but the results are a lot better looking from a rendering point of view.
While Blender render is way simpler to set up but looks kind of comic book like.
However if you are ONLY in to 3D printing, they both print the same ' )
So whether your in the Cycles rendering camp or Blender render the results are equal where printing is concerned.
Step 3: Vertex Color Using Cycles Rendering
To get the model set up for cycles there are a few things to do first.
1. Switch the rendering in the top middle of the Blender's layout.
2. In the lower window change that little clock icon (The time line editor) to the Node editor.
3. Give the mode a material clicking on the little checkered and it will show up in the node editor.
4. Next click the Object Data tab and hit the plus sign under vertex color. By default it will be called Col but you can name it anything you want.
5. And lastly click add at the in the node editor and add an go to input node> and pick attribute. It will show up in the node editor. Connect a line to the color input on your material node and under name of attribute give it the name you gave the material shader IE in this case "Col".
And your now set up to use vertex paint in cycles.
Step 4: Vertex Color Using Blender Render
How to set blender up for vertex color in Blender render is dead simple.
1. Make sure your rendering is set to Blender Render.
2. Add a material under the checkered ball icon
3. Under material options click Vertex Color Paint.
AND THATS IT!
I told you it was dead simple ' )
Step 5: How to Paint With Vertex Paint
To use vertex paint first change object mode to vertex paint.
By default your object starts as white and the vertex color wheel starts at white... This is not very useful because if you try to see if it is working because if you try to paint on the model your painting white on a white model and seeing nothing happening. So just make sure you change the to some kind color on the color wheel before painting.
How does Vertex color work? You can only where vertices's are so if you click face selecting masking next to vertex paint mode, you can see where the color will stick. This checked box is also a tool for making off parts of the model using the shift key to select what faces you want to paint.
Step 6: How to Paint Everything the Easy Way!
Now if you make your brush really big and paint what you think is every angel you can think of still you will find spots that you missed.
How do we remedy this? If you press N to open the second object properties window you can adjust when your view port clips to see inside the whole model and paint all the way thought the model. I use this method allot for doing a base color to start with, so when my model prints I don't have any embarrassing white spots.
NOTE: when doing this be sure to hit 5 to toggle orthographic to perspective view.
You will also notice this mode is partially hollow. This is to save on printing cost and material, if you do this be sure to leave an escape hole.
Step 7: Stuff on Painting
Since vertex is only painting on every vertices's that the model has you may not have enough control with small details on the model. So just apply the multi res modifiers and presto more vertices's to paint on.
Need even more detail? No problem just add another level of multi-resolution modifier and you can have as much detail as your CPU or GPU can handle.
Now every time you add more paint you will see these jagged pixely stuff that looks kinda yuck. To fix this open your brush menu and grab the Blur brush and this is your best friend. Its good for smoothing out colors.
Step 8: About Thouse Teeth
So say you don't want your skull to be a symmetrical. To add some character you wanna take out some teeth.
To do that just apply the mirror modifier to the teeth then select all the faces for that tooth and delete them.
Step 9: Getting the Model Ready for Printing.
Once you have your model the way you like to get it ready for printing first delete all the lamps or cameras you may have in the scene. If you have a big scene you might want to just open a new Blender file and append the objects you want printed to that file.
Next lets say we will pick a size we want to print the skull. In this case we will try five centimeters.
First Ill add a cube to the scene then change its display properties to wire.
Next I like to zero out the location of the skull and the bonding box. It makes it easier too tell size and proportions.
After that by clicking on the icon with a little sphere and cylinder we can select our measuring system of choice.
Finally now we enter the size of the bounding box and scale our skull. Why not enter the dimensions to the skull its self? Because it would distort the skull's size. Instead scaling to the bounding box lets us get a better idea of relative size.
Step 10: And the Last Few Steps
A few things left to do.
Once I am happy with the model I will apply any mirror or multi-resiluton modifiers and the size I will export it as Collada file.
Then I will upload it to Shapepways to see if it's printable.
It looks good after uploaded but when I check the color sandstone I get a warning for
Now I have a few options.
1. I can role the dice and check print it anyway.
2. I can rescale the model which will increase the cost of the model. I suggest scaling in Blender because Shapeways it can scale it but the model can lose the color.
3. I can try and fix the walls. Shapeways has a an option to fix the walls as well but you will probably lose the color so this too I suggest doing in Blender as well.
In this case I chose choice number two. I just scaled the model a little bigger. The model still has a warning about the wall thickness but from all the models I have made I will take the risk because I am confident it will come out alright.
So until I can save up some money and print this model out this is the end of this tutorial.
Enjoy the model. It has not been sized, colored, and the mirror and multi resolution modifiers are left on. It is up to you to color it and make the size you with.
Have Fun! ' )