10-03-2011 06:37 AM
Hi I'm new to building full avatars or meshes, but I been spending lots of time trying to figure out the process of how you go from a high poly count model, that is I guess textured with polypaint using zbrush but working also alongside photoshop with Goz. What I am trying to get at is let's say I have a model that is 3 million polys, then I polypaint it and also use photoshop. After that what would be the process of starting to get it in Second Life? I know I need to either do retopology with zbrush, or use the decimation z plugin. Or also I have 3D coat could use that to. But I'm kinda lost is polypainting, is that like ptex from mudbox? Where some how you can save out a file and use that file to bake in textures ontop of a low poly count model? An you have to have a UV map already built I'd assume for the low poly count model. I was thinking I could use something like unfold 3d to do that. But also what confuses me is this normal map. Is that needed? Because I read it's just about adding more details to your model using fake lighting, such as bumps an dents. Reason I ask is I'm trying to simplify the process first before I go into doing rigging, animations. So if anyone can just tell me the process of going from mesh to fully modeled and textured avatar. Then I can worry about doing animations and rigging later. I know there is lots of ways this can be done but just a clear method as what's required no matter what programs you use.
1. Build a mesh in Maya or Zbrush
2 retopologize it or decimate in zbrush or 3Dcoat
3. build a UV map with unfold3d or zbrush uv master plugin.
4. then polypaint in zbrush/photoshop or use ptex with mudbox.
5. then save out some how a ptex file or not sure how with zbrush save out a polypaint file.
6. Use maya to bake in those textures onto the low poly count model with a uv map ready.
7. The result would be something close to the high end polygon model you started out with in zbrush.
Then etc etc lol. Sorry if this is annoying but I'm really trying to get an understand over all this like overwhelming information and the vast amount of programs that add to the confusion along with trying to be creative and build my first mesh. I have a gorilla head started so far in Maya but nothing finished. Also trying out zbrush thinking I'll just try one of the models in there first and modify it to my liking just so I can get a grip on how it's all done first. Plus with zbrush it's as close to drawing in 2D I have found. Makes it easier.
10-03-2011 09:03 AM
However you do your modeling workflow, the final output needs to be Collada .dae format. If you use Maya, then use the Autodesk Collada export, either 2011.3 FBX plugin or standalone FBX converter (it depends what version of Maya you have). The Second Life upload does not use normal maps (yet). Those carry information about angle of the object surface relative to light sources for lighting and shadow display, without adding extra geometry. Since we don't use them, you would have to bake any shading into the simple textures we do use.
The most important thing for a real-time environment like Second Life is to make your geometry as simple as possible. Doing static photos or offline animations (like making movies) you can take minutes per image. In SL you have milliseconds per frame, and your object is one among many that has to be rendered. So think in terms of hundreds or thousands of polygons, not millions. Second Life also uses "Levels of Detail" at different distances. When your camera view is far away, you don't need to render as much detail. You can upload 4 separate .dae files with different detail levels.
Baking detail from a high polygon version into a texture is a valid workflow, it is commonly used in making game art.
10-03-2011 09:45 AM - edited 10-03-2011 10:03 AM
When going between high resolution and low resolution models with Zbrush, I prefer to use a program called Xnormal to bake the maps. It works really well, bakes out a wide range of maps and offers some extra helpful functionality. Here's a tutorial of the process of transferring high resolution polypainting from Zbrush to the low poly model's UVs using X-normal: http://eat3d.com/free_zbrush_xnormal_pipe