Frost: Vertex color blending issues with MParticles?


I am having some issues getting Frost to blend between two materials when using MParticles. I’m not sure if this is a bug in MParticles, a bug in Frost, or more likely I am missing something here.

I already referenced other similar threads about this topic:

…but I seem to be having an issue with MParticles specifically.

I created a very simple PFlow with just geometry placement, vertex color mapping, a Blend material and Frost. This worked OK:

I then created a simple standard pflow with two events, each with a different mapping value, and this worked OK with a Blend material and Frost. But when I tried a similar approach with a MParticle flow it doesn’t work.

What I’d like to do is have a MParticles flow that has colliding particles from different sources that I can mesh with one Frost and do material blending using the Vertex color channel (since MtlIndex won’t provide for smooth transitions between materials). This example from the previous post illustrates what I’m going for (see 00:45):

Could there be some sort of issue passing the Vertex Color mapping info from MParticles to Frost, or am I just doing something wrong here? I can send my Max files if you want to take a look at my setup.

I am also interested to know of a good method to use this Vertex Color map blending to properly blend between more than two materials when used with pflow/Frost. In my geometry pflow example I was able to get this to work somewhat, but not 100% successfully.

I also looked on the Thinkbox YouTube page as well as the Thinkbox software site and I can’t tell for sure but I swear I can’t find some of the old Frost tutorials. It would be great if a more in depth tutorial could be posted regarding this approach since I found it to be a bit confusing at first.