Vertex Color Interpolation

[Chris136]

I am trying to recreate a shader in Blender from a game engine. I want to paint dirt masks with vertex colors over tileable base textures.

So far the shader works perfect, the vertex color painting too.

But: I noticed that the vertex color interpolation between vertices in Blender seems not to be linear. In the game engine the interpolation is linear, so the output of the shader is different when the mesh is imported into the game engine.

I rebuilt the shader with UDK to compare. There the interpolation is not linear, too.

I searched for detail information but could not find any about this topic.

What kind of interpolation does Blender use for vertex colors and is it possible to change it or compensate in the shader with curves to mimic the linear interpolation of the game engine?

[Chris136]

After testing some more it turned out that the vertex color interpolation actually is linear. It's the vertex color output slot of the geometry node in the node editor that is not linear. Please can somebody shed some light onto the conversion that takes place in this node?