I'm working on achieving something similar to this stylized effect. I want my smoke simulation to be rendered in ‘layers’ with an arbitrary shader for each layer (so I can do thinks like edge detection for the outline).


My strategy so far has been this:

1. Slice the simulation volume into N 2d slices.
   
2. Make a render with each slice individually from the camera point of view. (10 renders per frame if N=10)
   
3. Composite all N renders into a single frame with a COP network (where I can do the edge detection).
   

I'm stuck on step 3. I've been able to make N renders per frame using a Wedge node, however I can't seem to find any way to load an arbitrary number of frames using a COP Node. I want the number of slices to a be a variable that I can change at will, but it looks like I can only load images with the COP File node, which only loads one image at a time.

Any thoughts on how you would approach this instead? Any suggestions on how to load in a bunch of renders per frame in a COP?

For reference, this is my current setup:


I do a volumeslice along N places on the volume, and then merge them together. Then I render with a wedge to render all N images per frame.



Let me know if I can be clearer!

you should be able to do it inside of a Loop COP

Thanks for the reply. This is actually what I tried first, although, it gave me an error when I tried to put a LoadFile inside of the loop cop, relating to the fact that the loop can't change the image planes / resolution. Although perhaps I had it set up incorrectly.

Here's the note from the manual with the restriction I ran into:

There are some restrictions placed on the COP network within the Loop COP. The network cannot change the frame range, image resolution, or add, remove, or modify planes (an error will result if you do). The Loop Data COP should always be connected directly to the first subnet input and all COPs within the Loop subnet should use it the first input instead of the first subnet input connector. The other inputs (2-4) can be used directly.