Gil,
Fair enough:
The avi file will be converted and mixed with a mp4 media file I use on my master RPI (which also in connected to a transmitter). This mixed media file is coupled to the sequence file on the FPP playlist. The group is the whole house RGB group. I put effects (multiple layers) on this group. I also put individual effects on certain models to highlight the music or whatever. The matrix fills a substantial physical space on my display, it's fairly large.
I play the mixed media file on the projector (HDMI) input. This allowed me to include some early messaging in the sequence (and have the resolution that a video file can have on the messaging), followed by a matrix as a physical part of the whole house effect. Looks very good in preview. I wish I could export the matrix from the whole house group. When I include the effects I put on the whole house group on to the matrix model, it doesn't physically match the whole house.
I might be able to this with a virtual matrix, but the file size and resolution would be a trade-off, and rendering time might be too long for my slow computer. I've not tried that yet. I've also tried to change the Buffer size for the Matrix model, but it will not allow me to increase the buffer size to that I require. If you have any other idea's I'm willing to try them!
As far as complexity: this idea seemed simple enough, but in actuality appears to be very complex.
Regards
John