I am creating a rain simulation. I would like to make a render pass with just the rain falling and then one with just the interaction with the ground etc so I can dial things around in comp.

I have the falling rain and the hit rain split into groups, but how would I go about rendering a simulation with the separate passes. Would this be a takes kinda thing?

Thank you in advance for the tips.

jball
I am creating a rain simulation. I would like to make a render pass with just the rain falling and then one with just the interaction with the ground etc so I can dial things around in comp.

I have the falling rain and the hit rain split into groups, but how would I go about rendering a simulation with the separate passes. Would this be a takes kinda thing?

Thank you in advance for the tips.

I think I see what you're trying to do, if you have gotten the hit rain and falling rain into separate groups you're probably halfway there.
I would use takes, and just change candidate objects in the render node in each take. But I've never really done this before, so there could be a better way.

That is what I am after. I am just not sure if I need to sim them differently or how that would work. Since the one rain (falling) is what drives the creation of the splatter rain, I am not sure how I could break this out at render time.

Thank you for the help.

You've probably figured it out by now, but I had to do this on my first big H project.

I assume you have (at least) two copy SOPs making the falling drops and the splashes. Just don't copy anything to the splashes particles in one take and then don't copy anything to the drops particles on another take.

How ever, if you require the detail that the drops to actually are in front of the splashes the way they are in 3D space, I'd to it with materials maybe.

Am I crazy for thinking this should be done with two different Mantra ROPs?

After your simulation. Create 2 new Objects named :: 1) Falling 2) Hit

Then two corresponding Mantra ROPs. Merge the falling group to ‘Falling’ and the hit group to ‘Hit’.

Then in the visible objects for your ROPs, set one to Falling, and the other to Hit.

There are million ways to do this, and there's no right answer. Have fun!


cheers,
-j