3ds Max vertex paint on the alpha channel

Hupie · Oct 2014

I'm currently trying to model terrain in 3ds max for use in Unity and I want to use vertex colors to blend different textures together. I use the vertex paint modifier to paint the colors but i can't figure out how to paint on the alpha channel of the vertex. I tried several combinations of the radio buttons under Channel under the Parameters rollout and the Display Channel options on the VertexPaint window. I made a shader with shader fx which should show me the alpha channel is being painted on but I cant seem to affect it.

Is it possible to paint on the alpha channel of the vertices using VertexPaint in 3ds max 2015? Can anyone confirm?

easterislandnick · Oct 2014

I think you need two modifiers in your stack, one for vertex colour and one for vertex alpha. I think thats how it works.

haiddasalami · Oct 2014

I dont think alpha channel works correctly. Looks like the R G and B channel works. Try this shader and see if it works:

http://www.polycount.com/forum/showpost.php?p=1672714&postcount=20

EDIT: Sorry meant the vertex color alpha slot in the vertex color node for ShaderFX. Though i am definitely painting on it.

Noors · Oct 2014

Never had issue with this. Yes you need one modifier per channel.
1 for color, 1 for alpha. You can't swap in the same modfier.

You could check the Tools>Channel Info, and see if you have something in the alpha channel (num verts > 0)
I guess shader should apply to the resulting mesh of the stack, but maybe you need to collapse the vertexPaint modfier to register it ?

Hupie · Oct 2014

I think I have the painting on the alpha channel working by using two modifiers instead of one. But now I'd like to view my 3d mesh with 5 different textures using all 4 channels (RGBA), but I guess this isn't technically possible in 3ds max because I'm using two channels (RGB and A) at the same time ?
Even just using the alpha channel to show texture blending seems to not work. I made a simple shader to test the alpha channel but I end up with a completely red material, despite the alpha painted vertices. Is it possible to show 5 textures blended in 3ds max viewport or am I stuck at 4 using only RGB? And shouldn't the shader below work (the alpha channel has been painted on) ?

3ds Max vertex paint on the alpha channel

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