[3DSMAX] [Unreal4] ... Vertex Alphas

RossHildick3D

Hello.

I have a building and I want to apply some dirt and grime through decal GEO within max. I have a plane with a dirt texture placed upon a wall and was hoping to fade some of the dirt to zero opacity using vertex alphas. However, setting this shows no result in the viewport OR upon exporting to unreal.

Has anyone been able to do this/know how?

Thanks

Obscura

Some screenshots from the setup would help. Show the mesh with the vertex colors displayed, and show the unreal material.

RossHildick3D

Just imagine a plane but one of the four verts had vertex alpha (in the editable poly options) set to 0 - this corner should fade to complete transparency, but it doesn't. also ignored in unreal.

RossHildick3D

verts in blue have a value of 100.

I was expecting the result to be that the edges were transparent but they are not. Wondering what I'm doing wrong. My hunch is that is has something to do with the shader? Right now, I am just using default shader in max.

Obscura

So I tried this out, and the alpha channel indeed doesn't work properly for some reason. At least I wasnt able to get it working. But other channels works.

Obscura

Or you could use alpha in the material, and just paint it out inside Unreal, with the vertex paint tool, and save that as default on that mesh?

RossHildick3D

hey, thanks for looking into this for me Obscura; I was hoping to have quite a few decal geo done this way to avoid using loads of different alpha maps. Plus it'd be nice to see in the viewport as I work, artistically