Model Creation: ZBrush & Milestone 4
Collage UV's, Normal Maps, and their Purpose
The latter end of week 3 we began to discuss methods of scuplting in Zbrush, high frequency textures, and normal maps. But before we practiced the methods we had to better understand UV maps, their creation, and their layout for our textures later on.
Since you're supposed to build in parts it only makes sense that you also UV Map in parts. This is to make sure all varying textures such as metal braces on wood can be textured separately and not cause distortions in their own maps. Then we exported our models as an OBJ to ZBrush, a 3D sculpting program that can work with millions of polygons at once in real time. Working with the basic tools, brushes, alphas, and masks we finish our sculpt.
Unfortunately Maya doesn't hold millions of polygons too well, luckily ZBrush offers tools such as preprocessing, decimation, and exporting of lower poly models. Meaning that if I create a model with over 2 million polygons I can change my subdivisions from 2 million to 1 million and so on until I reach a viable amount of polygons. Now, there is a limit. Dependent on how you want your low poly model to look (30,000 or less faces) it also has to maintain a similar shape to the high resolution sculpt. This could also make your later textures look strange.
Once you've exported your low poly and high poly models into maya you can then begin the "baking" process. This is really where week 4 started for all of us. Our job was to create 3 models and follow the pipeline that I detailed above. The baking process is simple and usually gratifying. Make sure your high resolution model is over the lower resolution one in Maya. This isn't hard at all because they both hold the same XYZ Transform information in their OBJ file. At this point it's best to check the UV's on the low resolution model for deformations and compressions. Once your UV's look solid you can begin baking.
Unfortunately Maya doesn't hold millions of polygons too well, luckily ZBrush offers tools such as preprocessing, decimation, and exporting of lower poly models. Meaning that if I create a model with over 2 million polygons I can change my subdivisions from 2 million to 1 million and so on until I reach a viable amount of polygons. Now, there is a limit. Dependent on how you want your low poly model to look (30,000 or less faces) it also has to maintain a similar shape to the high resolution sculpt. This could also make your later textures look strange.
Once you've exported your low poly and high poly models into maya you can then begin the "baking" process. This is really where week 4 started for all of us. Our job was to create 3 models and follow the pipeline that I detailed above. The baking process is simple and usually gratifying. Make sure your high resolution model is over the lower resolution one in Maya. This isn't hard at all because they both hold the same XYZ Transform information in their OBJ file. At this point it's best to check the UV's on the low resolution model for deformations and compressions. Once your UV's look solid you can begin baking.
Baking takes your high poly sculpt and bakes the density, lighting, and shape information into your low poly UV's. Meaning when you finally render you can create the better illusion of your high poly sculpt without having to render the high poly count.
Image wise the pipeline typically goes like this:
Image wise the pipeline typically goes like this:
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| Goblet (ZBrush Sculpt) |
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| Goblet (Normal Map) |
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| Goblet (Low-Poly with Textured Normal Map) |
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