View Full Version : LW 11 HV Volume Particle Popping

05-22-2012, 10:51 AM
Forum search reveals 3 topics on this subject... way long time ago. Things have changed. We now have Relative Particle Age gradient input for getting smooth, pop-free per-particle dissolves, etc.

Well, is something amiss in LW 11.1?

Take a look at the attached clip of some volume hvs with ONLY a RPA gradient dissolve texture. Starts out nice and smooth as more and more particles birth, each with a 45 frame lifetime, filling in the volume as desired and gracefully fading out, but then particles begin popping into existence at frame 45. I changed the dissolve gradient to classic Particle age and obviously get the same result, because there is no +/- randomizing of lifetime. As for the gradient, it's a simple 100% @ 0.0, 0% @ 0.15, 0% @ 0.42, and 100% @ 1.0... that is, particles are 100% dissolved at birth, fade in full over 6 frames, stay 100% opaque for 12 frames, then fade out over the remaining 26 frames. Particle Size RPA gradient goes from 30% of 10m to 100%.

So, what the heck is going on?

The emitter is nothing special... just a very long bar 1 m square by 40 m long emitting 300 parts/sec via a 10 m Vibration (0% variation) and 0 particle resistance.


05-22-2012, 09:14 PM
Can you post the scene as well, so we can see the particle/HV settings? I agree that the popping seen sounds broken, and it is likely worth fogging regardless, but without the scene it's hard to be certain.

05-23-2012, 09:02 AM
I figured that would be the case. I'll have to rip the particles out of the scene so they're stand alone. For now, I've tweaked the HVs so the popping effect is minimized to the point where it sort of enhances the effect I'm after. I'm rendering the scene now, so I'll get to it a couple days from now.

05-23-2012, 10:06 AM
Are you using align to path (defaults to ON) in the HVs? That can make things pop around if they slow down or speed up too much.