View Full Version : hypervoxels help

05-12-2009, 07:33 AM
I've rendered a 28 second animation of a particle emitter with some hypervoxel volumetrics to simulate smoke. I need to go back and re-render out a smaller range of these frames because of a camera change and noticed that the effect doesn't sync up. I've tried rendering from the original scene and overlaying them on the original frames in photoshop and still the hypervoxels are slightly different.

Are these effects randomized every time you re-open the same scene? Has anybody run into this?

05-12-2009, 08:27 AM
Did You save particles simulation, with *.pfx file ?

05-12-2009, 09:10 AM
No. I just assumed that the particle and volumetric settings would remain constant when I saved the scene file.

05-12-2009, 10:41 AM
There is a tick box under particles that forces randomization.
But the best bet is to save out the particle animation to a file.

Interesting to know that LW does randomize it's seed everytime LW is started.

05-12-2009, 11:21 AM
So the box next to "Fixed Random" should not be checked if you want the particles to stay the same at each restart?

So I'm screwed?

05-12-2009, 11:55 AM
So the box next to "Fixed Random" should not be checked if you want the particles to stay the same at each restart?

So I'm screwed?

Should be checked. I think it is by default. You may be screwed. :(
Sometimes it is faster to do it again than to try and find a workaround.

05-12-2009, 01:10 PM
or u could just render a few frames eitherside of the range ur re-rendering, then crossfade between the two different renders during the overlap.

05-12-2009, 03:24 PM
As I understood it ‘Fixed random’ is a random emission which is fixed for that setup. Unchecking this gives random emissions each time the animation is previewed.

I have in the past got variations in the emitters as I have worked on a scene, closed it down / re-opened it etc, but these have been brought back into line by pressing calculate (Ctrl X) or FXBrowser ‘Start’ which recalculates everything.

Other than that, its saving out a .pfx file

Rebelhill seems to have the answer

05-12-2009, 03:58 PM
Well thanks for the suggestions guys. I don't think the crossfade is going to work. I'm just going to have to add a new cut to fix this. The reason that I originally needed to alter the camera animation was to move some vibrating particles out of frame. It's always something.

Save pfx. Save pfx. Save pfx...