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Polypaint to Decimated model

ZBrush Usage Questions
#1

Alright. So I have my highres model and I want to paint on him so I can get all the details. However, I need a lower res model for my game. So, what is the best method for going about this?

Can I paint on high res (with UVs) and then decimate my model and export the resulting mesh with the texture made previously? I’m worried I might lose my painting if I do that. I considered getting the UVs from the decimated model and applying them to the high res one so that I could pull the textures off of the high res and get the mesh of the low res, but I don’t know if that is possible.

Any help is appreciated.

#2

Usually what you want to do is have your lowest mesh UVed to the same as your highmesh.

You can do this in different 3D app or use the UV Master plugin for Zbrush.

Feel free to paint in your highest SubD, even if it millions. Aslong as your highest resolution mesh UV’s match the lowest then you should be okay.

If you don’t have any lower subD for some reason you can create them by using Tool:Geometry:Recreate Lower Devisions. And then export that low poly mesh to a 3D app or UV that one with UV Master.

If you have already painted your hi-res mesh but DON’T have it UVed, then

-you can store your Morph Target in Tool:Morph Target: StoreMT., go to your lowest subD level and import an UVed low poly mesh, then hit Switch under MorphTarget.

OR

-UV map your hi-res mesh using UV Master and export the Texture map(tif/psd/etc) and the low res mesh(obj) into what ever program you want.

You don’t really need to worry about decimation if you plan on doing it for a game as generally the meshes are pretty low. Say your hi-res is 5million and your low res is 10,000. you only need to export the base mesh (lowest subD) [Decimation is more for like 5million to 50k; in which you still want a hi res mesh just not as high.]

You basically need 3 things

-Low polymesh for the game
-Hi poly mesh with detailed sculpt/colors
-Texture map generated at the highest subD level and exported.

The two meshes need to have the same UV layout.

Hope this helps.

Let me know if you have any more questions.

#3

The only reason I need to decimate it is that I added some spikes (sorta) to my mesh, and when I go to the lowest subdivision level, all of the spikes disappear (they flatten out). I tried exporting the lowest mesh just to be sure, and yeah, I totally lose all the details that I want. So I figured if I decimate it, it should keep those spikes without needing such a high mesh level. I’ve never actually had to do it this way before (normally the lowest subdivision works) so I don’t know what is involved.

I was wondering if that workflow would work though for my decimated model. I figured I’d make two copies of my mesh and decimate one. Then I’d take the UV’s of the decimated one and paste them onto the high res one. Should that work?

Thank you for all the help though. That was so much more helpful then some of the responses I’ve gotten from others when I ask this question.

#4

Have you tried tweaking the verts on the low polymesh to make some rough spikes on it? Just pull up the vertices in a basic 3D app and apply your normal maps and it should look decent and just tweak ur UV’s in your 3D app if some stretching occurs. if not, try to retopo your mesh by using your hi res mesh as a reference. you can do before you export your maps using zbrush or after using your standard 3D app.

You can use decimation master to make a much lower res and import that to say Maya and generate your maps from there if thats easier.

Here is a video to get u familiar with retopo in ZBrush.

http://www.youtube.com/watch?v=-Fdog0y9jVQ

Hope this all helps.

I know its difficult to find information sometimes about specific situations.

Just in the end know you need to have your lowmesh uv’s and hi-mesh uv’s be exactly the same for it to work.