Depth Sort with Fluids and Particles

[david-schoneveld]

I've noticed that when you render particle clouds and fluids that inter mix you don't have expected results.
take for example:
import > Explosion > Blast
then create a directional particle emitter (it should be in the middle of the fluid.)
Next make the particle a cloud and play out about 15 frames and render.

What I'm getting is the particle rendering completely ontop of the fluid. even tho the fluid are surounding the particles.

[stickdude]

yep, you'll also notice that 2 or more transparent fluid boxes don't look as nice when sw-rendered as it does in hw-render.

[david-schoneveld]

I hear people talk about rendering in hw, but when I do I get a black frame. How are people rendering in hw?

[david-schoneveld]

ok well I can with the hardware render buffer but that looks like terrible, so does anyone us hardware rendering it looks so bad, and doesn't respond to lights.

[duncanbrinsmead]

The renderer integrates the volume spans from the fluids by default as a single span of density. This works ok with opaque surfaces, but may not be sufficient when combining with other volumes, like particle clouds, especially when the fluid has a very defined surface.

In these situations you can enable volumeSamplesOverride on the fluid and increase the volume samples.

Duncan

[duncanbrinsmead]

Also in terms of hardware rendering, one can only do playblast style hardware renders of fluids, and as mentioned, the lighting cannot be adjusted( it is a single directional light aimed along the fluid's diagonal ).
One can get nice results for some things, however. The graphics card may make a difference. There are display attributes on the fluid that affect the hardware rendered quality: slices per voxel, voxel quality.. also turn off boundary draw. I found that the hardware draw was much nicer on an Irix box, due to the floating point hardware transparencies.

Duncan