Painting dirt onto tiled materials?

Hey guys,

Here’s a very rough beginning scene.


I want to add some painted detail on the floor (some soot under the stove, dust/grime in the corners).

Now, the floor is a single poly mesh. I was excited to use vertex painting using a vertex color node - but my understanding is that it won’t work with a single poly mesh. From my experiment, even a pretty high poly mesh can look janky when vertex painted.

Is there a way to go about painting on a tiled material - on a very low poly mesh - that gives smooth results?

I think I know the answer, but thought I’d ask.

Putting it differently: If you had to add some detail to this floor in specific areas, how would you go about doing it?


You might just do it with a texture mask, you could save that as an alpha channel for that wood texture.

just use dirt decals to project on any surface you want and high-res as you like

This is what I was thinking. Should I be concerned about performance? How resource heavy are decals?


That really depends on the scale of your project and how good your culling is or how you handle those things.

Vertex painting would be ideal, you would use a texture to control the blending between dirty and clean, instead of just relying on the vertex blending. You could get away with a pretty low poly plane, around 32 tris for a floor that large.

You could also add a black and white mask making use of the lightmap UVs indicating what is clean and what is dirty.