Rebus B

So the streams work, kind of. There is no problem splitting off branches with a Delete sop by using the stream name to separate them. But using a Material SOP to assign different shaders to each stream without deleting them does not work. It does not recognize the grouping. I tried all the toggles and label settings to no avail. It renders the pop object with a third shader, the one I used for the floor, and ignores the Material assignment.

Also had some difficulty separating the data from POP fluid nodes in DOP network, where it seemed to step on each other's data even though in different stream branches. Tried it with grains too but wound up having to just use one PopGrain node and wrangle attributes in each stream to get it to work.

So I see how streams can separate data but it does not seem to be as isolated as if using individual particle objects. Am I missing a step?

Perhaps a better way to state this: What is the best way to simulate multiple particle (or other DOP object) systems, each with their own independent behaviors and rendered with different Materials, in Houdini?

Is it possible to set up a DOP network to have two (or more) popobjects? The goal is to have multiple particle “styles” (with independent source, behavior and specifically Material settings) that interact?

This is may be post-Maya thinking, having different self-contained particle objects set up this way. In Houdini using groups/streams and initial attributes set in the emitting SOP are a good way to have one popobject have different behaviors that work together but the problem then is splitting them into separate Objects with different Materials. The DOP I/O sop can only pull in one DOP object, and the solver seems to only like having one object to work with.

My naive approach was to merge two POPobjects before connecting to the POPsolver but there is no way to identify them to the POPsource nodes, so each contain the entire particle system.