CGTalk - two particle questions

View Full Version : two particle questions

mogwai

12-18-2002, 05:53 AM

helloEverybody,

I have two questions about particles:

1. using blobby surfaces, colliding with a ground plane, and affected by gravity and goal weight, I am getting a lot of jiggling. I can't remember the setting to reduce this. I have tried adjusting oversampling and resilience on the colliding geometry. Is there something I've missed?

2. after working with a file with dynamics in it, the particles start doing strange things in the render. ie. particles jump into different positions between frames...it's as if I've run two different simulations and cut between two sequences. or, particles will disappear for a few frames and then reappear.

any help would be appreciated.

kag122

12-18-2002, 08:04 AM

for the first problem i dont understand quite what is going on as in jiggling. Are the particles bouncing up and down or left to right? Oversampling controls sub samples between frames and resiliance control the bounce off the collision object .

For the second problem its an easy one to fix.

Goto the solvers menu and cache your particles. This should fix the problem.

mogwai

12-18-2002, 01:48 PM

thanks for the help with the second probloem, I cached the particles and that solved the problem.

as for the first problem, I am beginning to believe it is a texture/lighting problem. the particles seem to move up and down so it would be a resilience issue, however I animated resilience and conserve down to 0/0.1 and still have that jigger/flicker? effect.

mogwai

12-18-2002, 01:56 PM

lowkey

12-18-2002, 03:40 PM

well, did you already try to decrease the 'conserve' attribute on the particles' tab ?! this should take the original energy off your emitted particles and make them stop jiggling.

upps, just read your post again ! :rolleyes:

kag122

12-18-2002, 09:13 PM

I've had those problems with jiggling before at work. I simply replaced the collision object with an exact replica and it fixed the problem. Could it also be that the particles are trying to get to the goal and your collision object is in the way?? the particles will jiggle because of goal settings if this is so. Check the help files on what each setting in the goals attributes means and you'll see what i mean. :) most of your answers will be found in the help files

mogwai

12-19-2002, 01:02 AM

Thanks a lot for your advice,

I certainly learned and tried a lot before realizing it was the goal smoothness...everything from animating resilience, conserve, inherit factor and even gravity. Believe it or not at one point I got really frustrated because I didn't know you had to recreate particle caches to see the effects of these changes. argh

five hours and twenty renders later, it's almost done.
:rolleyes:

kag122

12-19-2002, 01:57 AM

Glad you solved the problem. I knew it was the goal smoothness as soon as i read your last post.

It would have solved you alot of time by just reading the help menu. Alot of people on these forums waste alot of time here, changing setting such as inheritance and gravity, whcih have absolutlely nothing to do with their problems.

Just some advice, and i'm not trying to be offensive so dont take it that way, if you had read the help topics on what each setting does in the help such as inheritance, chaching etc it would save tonnes of time for you, and also would give you a better understanding of what you are actually doing. In turn you will get much better at it.

CGTalk Moderation

01-14-2006, 12:00 AM

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.