Render vertex colors over textured materials

I want to apply vertex coloring to one of my models that’s also textured. I would like to multiply the vetex colors over the texture (the vcolors will simulate AO and shadows). How would I go about doing this?

If possible I’d like to be able to preview it in the viewport together with transparent textures, but also in renders.

Also is it possible to brighten all the models vertex colors without doing it manually?

Thanks!

baking the vertex color. you can then lighten up the whole thing in gimp.
have a look at this tutorial for the how to.

I am trying to make a tree for a Doom 3 mod where I will use tiled textures for the trunk, but to break it up a little I want to have the vertex colors influence it as well and make it darker/lighter in places. Is this possible to render it (without baking to an image) in Blender? It’s possible to render it in Doom 3 so one would think it’d be possible in Blender as well.

Also is there something better than ‘Dirty Vertex Colors’ to simulate ambient occlusion with vertex painting? I’m wondering because that seems to work best with meshes that have no floating geometry. I want something that would make darker vertex colors the closer it came to an intersection between to meshes.

It is possible to bake vertex colors to a texture but is it possible to go the other way around a bake vertex colors from a texture as well? If so, then how do I do it?