What has proved to be the best way you all have found in rendering a particle rain sim?

Currently I am just rendering the points with heavy velocity blur, and that works to an extent, but for things that are a little slower moving, are there better ways of doing this?

Instead if single particles, have them be little groups and surface them and then render the mesh?

Just wondering how others have found to be the best solution for the best looking rain.

Thanks!

Points tend not to light or shadow as well as you would like.

Instanced primitive spheres or even pyramids (platonic solid sop) can be good for heavy downpour, especially if you want to get a shafts of light and shadow.

Sprites can be good for somethings like splashes and overhang runoff.

Metaballs with a convertmeta will give you a surface that can be exactly controlled, like with slow motion rain. For maximum efficiency look into the metaball procedural, as you can polygonize the metas at render time instead of dumping tons of polys to disk.

I am assuming then with the pyramids approach that we would use the copy sop to pass around the geo to the particles.

Very cool approaches. Thank you so much for the ideas.

I would use copying for visualization, but actually use point instancing for rendering. Much quicker.

Also if you use sprites, you can use the copy sop and/or the sprite sop, but in the end the sprite procedural is much more effecient for large amounts of sprites.

Very cool.


Now things are moving along, but now with the geo I have lost my motion blur. At one point when rendering point I was using a point sop with a added velocity to drive the blur, and then later changed that to actual velocity in the simulation.

What is a good way to get some blur back? I tired adding a trail node, but that did not seem to help at all. Is there something I am missing.

I am still new to this. I know how I would do this in Maya, but I am making the transition.

Thanks again!

J

Go the Attribute tab of the Copy SOP and turn on “Use Template Point Attributes”. This will copy attributes to the geometry so velocity attribute blur will work.

Cheers!
steven