Vertex paint with an opacity masked second texture?

Development Rendering
1

Hi

I’m learning about vertex painting, i’ve managed to get 4 textures into one material and paint using the RGBA values, but is there anyway to use a .tga with an alpha channel to go over the base colour? For example, rust with a transparent background with an alpha channel.

I tried hooking the alpha channel straight up to the opacity mask but it made the whole material adhere to the mask.

Anyone know what i’m on about, and what nodes i’ll have to add?

ALSO: Important question. Sometimes when I vertex paint, the second texture comes through on the edges but its black in the middle. When I vertex paint every vertex instead of the asset being the second texture, its just black. anyone know how to fix this?

Thanks in advance.

2

What you would want is to use the Linear Interpolate node to blend your rust. The alpha of the rust goes into the Alpha of the Lerp node. The layer you want under the rust goes into A, and the rust RGB goes into B.

If you want to vertex paint the mask, multiply the Alpha by a vertexcolor channel before hooking into the Lerp alpha.

The same thing works with “MatLayerBlend_Standard” which you can use to blend entire layers which contain a group of all pins called “Material Attributes”. the blend function is basically just a bunch of lerps.