Introduction: How to Make a Low Poly Game Model Look Way More Detailed Using Blender and Gimp
So you want to make a game but you have a computer that can't handle graphics all to well and but you still want to make something that looks wicked. This is a method I made up when trying to make games .
A formula I like to live by is Fun > Work. If you work on something so much you start to hate it you failed.
I hate working on UV maps and spending all day matching up faces on a stretched out map, but I like to make models that look interesting and have lots of detail. So hopefully this will help anyone who hates making UV maps too.
This tutorial I will show how to make some nice looking textures out of a high poly art model and apply them to a low poly model that will be used in the game.
This tutorial I will not go in to building the model as that is a tutorial all to it's own, I am just going to show the work flow to making a high poly model in to a texture and then make a low poly model of it to add in the game.
Step 1: High Poly Low Poly
This is a vehicle for a flight game I am making.
The first two images show what the craft looks like with some a multi res modifier added to the model.
The second two images are what it looks like with the multi res turned off.
If you look at the amount of vertices's on the fist two images they are at 59.268 which makes it look vary smooth but if it was in a game it will use up a lot of unnecessary memory. In the second two images with the multi res modifier turned off it the vertices's are at 3858 which makes it well enough for in use in a game.
I like to build most of my models with a multi res on the entire time so I know how it will look one it is added. Multi resolution modifiers are good for making a model look smooth but I don't ever apply the modifier until I am finished.
Step 2: Fun With Wire Frames
To show what high poly and low poly looks like I added a wire frame modifier to the model and made its material something bright to show it off X ray style.
The model on the left is good for looks, the one on the right is better for game play.
To make a low poly model look like I high poly model I am going add a material to the high poly model, give it some vertex paint then render it as a texture. Once a texture has been made I am going to take the texture in to Gimp, a free photo editing program, and add a little more detail. Then after all that I will show how to make a UV projection on the low poly model. When its all done we should have a low poly game model that looks closer to the high poly model.
Step 3: Material Ideas and What Are Matcaps?
I am working in cycles because it makes more detailed realistic lighting.
To get an idea for what kind of materials to use try out the Matcaps.
Images 1 & 2 show Matcaps...
What are Matcaps? I really don't know but if you press N a properties window on the right opens up and under shading there is a slot that says Matcaps and check that box. It opens up a number of materials that you really can't use for rendering but they can give you an idea of how your model will look with a variety of ma teals or maybe I just like them because sometimes I get sick of the default Blender gray.
After playing with Matcaps I decide I would like to make my aircraft look shiny but I am going to add some vertex color to it. I start to add a few materials to the craft. One for the skin, one for the cockpit glass, one for the tires and one for metal parts like landing gear parts.
Step 4: Setting the Scene
Take your model select all its parts then press (Shift D) to duplicate it and then press (M2) to move it to level 2.
One model will have lots of detail and subdivisions and the other will be light weight made for gaming.
To set my scene up for vertex paint and then rendering there are a few things I do specifically for making a game texture.
1. I set the model up in a default pose for example parent all its objects to the main body then press Ctrl A to set the models default location to 0. This means anywhere it gets moved I can always bring it back to this pose.
2. Make sure the rendering is in Cycles which is at the top middle of the your view screen. Then I will go to the camera icon and set up my quality settings.
My quality is normally
Output: PNG, RGBA, color depth 16, 0 compression
Sampling: preview 0
3. Next I will add 6 (point) lamps to the scene placed in front back above below and to the sides of the craft. This is because when it is used in the game I want the lighting on the craft to be vary neutral looking because it will be moving a lot. (Picture1)
4. Set the camera in scene to orthographic
5. I apply my multi res modifier to the model and then add a few more subdivides to the model by pressing the subdivide button on the right as indicated by the arrow in (Picture 2).
Step 5: Vertex Paint in Cycles
The reason we added extra subdivisions to the model is the more subdivisions you have on the model the better the vertex paint will look. Also this model is only for adding vertex paint and making textures but this model will be way more high poly then you will ever want to to be.
Since Vertex paint was originally made for Blender render you have to add it to your materials in a special way.
1. Under the Object data icon, which looks like a triangle of dots in
the right property window. Press the + next to vertex colors which adds a vertex color slot called "Col" unless you rename it.
2, Change the Time Line editor at the bottom of the screen to the node editor. Then click Add>Input>Attribute, then in the text box type Col or what ever you named the vertex color in object data. And finally drag the yellow dot next to color and drag it to yellow color dot on your material.
Now change the object mode to vertex paint and now when you paint on the model you will be able to see it when you render your model. NOTE: this also makes it possible to 3D print in color, if your using Shapeways sandstone material.
Now paint on what ever colors you want. Vertex paint has a color picker, be sure to change the color to something other then white ells you won't know you are painting.
A tip. a way to get the colors to look smooth is paint them on in a general way then use the blur brush to melt them softly together.
Note: In the images above I removed the top jet rotor because it will be moving any time the craft is flying so this will be textured separately.
Step 6: A Custom Paint Job
After giving your model a vertex paint job and getting it all snazzy looking ill hit Shift Z and see how many samples it takes to look really nice. This is indicated by a counter in the middle of your view port screen.
Unlike Blender render which rendered out until it finished, Blender cycles all looks hazy and will just keep sampling and the image will keep looking better and better. NOTE: Make sure you went in to sampling properties and set preview to 0, ells you wont see much because its set to only 10 samples.
Once I see how many samples looks good, I'll type that value in to the render level under samples in render properties.
Next the scene camera. If you haven't noticed Blenders camera isn't the easiest to point and click, but hear is the trick. Where ever your view is on the screen, if you press Ctrl+Alt+0 and this will reset your camera to any position you like in a snap.
Making the textures will take some practice of what ones will you need. For example this jet's wings rotate so I can take them off to have a more clear area to work with. also the intake blade I took off because it will be moving when the craft is flying. Next I will set the orthographic scale (this is under the projector camera icon) to show as close to the craft as possible.
1. Press 1 for a front view Ctrl+Alt+0 to snap the camera to that view and render it F12 and save that image.
2. Press -1 for a back view Ctrl+Alt+0 to snap the camera to that view and render it F12 and save that image.
3. Press 3 for a left side view Ctrl+Alt+0 to snap the camera to that view and render it F12 and save that image.
4. Press -3 for a right side view Ctrl+Alt+0 to snap the camera to that view and render it F12 and save that image.
5. Press 7 for a top view Ctrl+Alt+0 to snap the camera to that view and render it F12 and save that image.
6. Press -7 for a bottom view Ctrl+Alt+0 to snap the camera to that view and render it F12 and save that image.
Thats most of it but I may do this for some parts by them selves as well. This part is the longest because of rendering times.
Step 7: Using Gimp
I used Gimp for this because it's free for any one to use. Photoshop works if have that as well.
I like using a BIG texture to work with so the model retains the best details. To do this I will look at the pixel size of each image and do a little math to find how big to make my texture in Gimp. Once I have this size Ill open Gimp File>New, enter the size you want then select Advanced Options and from background select transparency.
Select the window of this giant box you just opened and then under file>open as layers, select every image you just rendered. (Hope you rendered them all as PNGs)
Then I start arranging them all over in any manner that fits pretty well and then ill usually crop the image down to save on size a little. (Picture 1)
After I have my big texture I might add extra details like flight numbers, aircraft decals etc and then save the whole thing, as well as exporting it as a PNG that I will use as my texture in Blender.
Step 8: Meanwhile Back in Blender We Will Dissolve Some Loops
Multi-res modifiers are the best for making things look smooth however in doing so they add a lot of unnecessary loops to the mesh (your model).
What are unnecessary? Well mathematically the computer is not wrong for adding all these loops to the mesh frame. We asked for them to make it look soft but now we don't need all of them. Less is more goes a long way when making a game asset. So to save memory lets start stripping this model down some.
1. On the copy of the model I moved to level 2 I will bring the number of resolution on the model down to 1 and I apply the modifier, making the changes permanent. This will make it look still a little smooth and I will strip it down a little more.
2. Press Tab to edit and then press Shift and select a loop with the edge selector.
3. Press X and select resolve edges.
Note: If you have a mirror modifier added to the mesh, leave it on and
reduce one side as much as you can before applying it. It saves some work for you. Then apply in and reduce the loops around the middle as well.
Note: I highly recommend using devolve instead of deleting the loop because blender will automatically change the mesh some to compensate which will totally mess up any UV mapping you may have done. However if you use devolve edge, it does not mess up your UV map!
Step 9: A Few More Tools to Strip a Model
A few other tools you can use to reduce a mesh
You can bring edges together by selecting the edges you don't want then press X to bring up the delete menu and hit Edge Collapse.
Merge can help bring a lot more together faster by selecting the vertices then pressing Alt+M to merge them.
If you have a spot where the UV map just is not sitting right on a spot, you may have to delete the faces on the model and put them back on differently using the F tool. Just select your edges where you want a face and hit F to add a new face.
NOTE! All of these tools will mess up any UV maps you may have added.
Step 10: The Dreaded UV Mapping ;. (
There is a reason I came up with this method. I hate painstakingly unwrapping UV maps. If you can do this, you are gifted ' )
How to get a texture on your model.
1. Add a material to the model. You can do this by clicking on the little ball with checkers on it in the right properties window. Don't worry about its color, for now I would leave it white and drop the specular to 0%. Specular is how shinny it will look on the model in the game. I mess with this after I get the texture on the model.
2. Click on the checkered square, this is the texture properties. Under type; click image or movie and then select your texture that you made in Gimp.
3. At the top of the scene there next to help, to the right change default to UV. This will split the screen in to your model on the right and a gray square on the left.
4. Next to word image, click the texture you made. Last before you can start, make sure you ether press N and change texture to solid or change the view to texture. Yes, you may have done this in default mode but in UV mode everything starts over.
5. Now to start putting adding your texture on your model you have to start selecting the faces and then while in the right window press U to bring up the unwrap window and add I use project form view. This for me is the best way I know how to make UV maps that doesn't make me pull out so much my hair. I am practicing to get better but if you want a quick and dirty way, this works.
Step 11: And Here Is What We Have in the End.
So after striping some of the dentals off a high poly model but then overlaying a texture made by the high poly model on to the new lighter model you can get a pretty nice, not perfect but nice model that should work smoothly in making a game.
Hope this helps you out.
Enjoy building? ' )