Dynamics Optimization- collision with 8000 objects Cinema 4D

[annalord 0]

I am currently working on a scene with a planet that has 8000 small objects orbiting it. I have attempted to set up the scene is as simple a way as possible, the planet is simply a sphere tagged as a collider with an attractor inside it, the 8,000 orbiting objects are created using a cloner with a flat plane inside it tagged as a rigid body. To get the desired pace I have slowed the project dynamics speed down to 0.2%.

 

 

Everything is working BUT is agonizingly slow, almost impossible to work with in any reasonable way. I am working on a brand new macbook pro retina, 16gb ram, quad core etc everything maxed out and although this is obviously not as much of a workhorse as a mac pro, I imagine there must be some way for me to optimize my project to make it more manageable

 

Since the project operates at only 0.2% speed, a ton of calculations must be done just to get it do the point I am interested in showing, ie. all of the flat planes must collide with the planet violently, bounce off, then come back to the attractor which at 0.2% takes a couple thousand frames, I don't have to render all those, but so far I have had to calculate the dynamics for those frames into the cache even though the part I am actually interested in making a final render of is 6000 frames deep. Am I correct that this must be done this way? Perhaps I could start the project off at 100% speed, then keyframe it to 0.2% once everything has collided and the dust has settled so to speak (the part of the motion I am interested in rendering). Right now for 7,000 frames my cache is 25 gb which seems insanely massive and unwieldy.

 

Other than that, does anybody have ANY tips on working with collisions/dynamics on such a huge scale? Ways to optimize? Other approaches worth exploring? My end goal is simply to have a planet with thousands of these flat planes slowly dancing around it but at this point the weight of the calculations is really bogging things down.

 

Thanks so much!

 

Anna

[eliss 0]

A rule of thumb for me that I like to follow ... if it gets too complex I'm probably doing it wrong. I would try and use an Xref object to pull in a more detailed model and have a simplified object for the Reference. I'd accomplish this with Thinking Particles not ridged body tags.

[Mylenium 0]

Well, your whole setup sounds like it could be done with some simple bog standard effector animation without any dynamics ever getting involved at all, but without actually seeing it, it's impossibel to tell.... Still, I realyl think you're trying to be too academic here and wasting a lot of energy on something that will go for naught...

 

Mylenium

[iline 0]

What Mylenium said. If you're employing dynamics then I assume accuracy isn't your goal anyway... In your situation you can use one dynamic object to drive the PSR of thousands of others. Those other objects can be instances or xRefs, and therefore the calc your scene causes is minimal. Even 8,000 flat planes animated would be a pain to animate, cache and render, so think strategically. Dynamics is probably over-egging the pudding.