View Full Version : Emitter calculation weirdness

05-05-2008, 02:29 AM

I'm working on a fairly straightforward effect using a particle emitter and a collision object, but I'm getting an odd result when I calulate the particle motion.

Basically, I'm trying to make a sort of liquid flow over a wheel rim. I brought in the subpatched rim and made it a collision object (Object-advanced) with a Stick mode. I added a null with an emitter, gravity at -9 m/sec, etc. Both objects in default group. When I scrub the animation things look fine; all the particles slide over the radius of the rim and collect at the bottom.

But when I hit the Calculate button a bunch of the particles fall straight through the collision object. Scrubbing and previewing the scene reflects this. However, if I render a frame, the rendered frame looks correct (particles aren't falling through the wheel), and when the frame finishes rendering the particle motion appears to revert back to the original, correct motion.

Then, if I save the motion it saves it as the correct motion. I can clear the scene and load in the motion to an emitter and it plays back correctly. If I save the motion generated after I hit Calculate it saves that incorrect motion; that incorrect motion will load.

So any guess as to why "Calculate" is messing up the motion but rendering a frame "cancels" the calculation?

I'm running LW 9.2 on a dual 2.5 Ghz G5 Mac.


Shawn Marshall
Marshall Arts Motion Graphics