Dynamic Paint with multiple Vertex Colour maps


I want use Dynamic Paint, but the canvas object already has a Vertex Colour map to define its substrate colour in a Cycles render. The Dynamic Paint is done in another scene onto the same object using Blender Internal Render and Dynamic Paint.

The trouble is, I can’t get the BI Render to choose the Dynamic Paint Vertex Colour map rather than the the substrate Vertex Colour Map.

In Cycles you can use an ‘Attribute’ node to choose which Vertex Colour map, but I can’t see how to do it using BI materials. Can anyone help please?

Aha, I found out the problem.

I manually created a Vertex Colour map for the canvas of the Dynamic Paint of object in question. In doing so, the new Vertex Colour map inherited colouring from the previously existing substrate colour map used in Cycles; it wasn’t starting as plain white!