Particle system problem

[terry.lee]

Hi.

I have a particle system coming from a shaped emitter. The emit start is set to -250 to enable the correct of particles to be visible at frame 0. All worked fine. When I changed the emitter the particle system started to only emit a few particles at frame 0 building up to the right amount about frame 120? I played about with all the parameters and tried re-creating the particle system but same result?

Anyone have any ideas why this has happened?

Thanks,

Terry

[pened]

Hi,I´m sorry I´m Maya user but I think you have to make new cache.

[terry.lee]

Thanks, but not sure about that?

The particles at correct after about 120 frames and thereafter. No matter what I do to the values prior to frame zero it is as if the animation starts from frame zero. There are a handful of particles at the start and these grow up to about frame 120 then all is OK.

The system emit start is set negative so that it is fully running at frame zero but still acts as though the emit start is 0?

Anyone any ideas?

Many thanks,

Terry

[terry.lee]

Further to this:

If I switch off the Position Object so that the particles emit from the PF Source emitter I can control them as expected e.g. any negative start times ensure that the particles are fully visible when the animation starts at zero. It is just when the emitter is added that the problem occurs!

[krueger_1]

It's hard to say without seeing your setup. Can you post the scene (if you can, saved for Max 2010)? Or at least some pictures if you can't.

[terry.lee]

Hi Mike.

File attached.

I have been working on this for a while and the particle system has functioned correctly all the way through. This last emitter shape seems to be the problem. If I switch off the position object in the PF then I can control the particle system as expected with negative emit start times. As soon as I switch the position object back on it acts as though the emit start time is set to 0.

Many thanks,

Terry

particle_system.zip

[krueger_1]

Your emitter object doesn't have any polys until frame -2 because of the morph, so there's nothing to emit particles from. If you make a copy of the final mesh you want to emit from without the morph and make it non-renderable, then you can birth particles the whole time.

[terry.lee]

Thanks very much Mike!

As ever, you are a star!