I’ve got a animated object that moves very fast through my scene. It jumps a fair distance per frame and I’m having some issues trying to keep the smoke residing in the initial position while continuing to emit as the object gets further away.
Imagine a football being kicked and traveling through the air fast as the camera remains in the same position but following the trajectory of the ball object.
Image attached with my settings.
I was hoping that someone could tell me some settings or a link to a tutorial that covers a similar scenario.
There is just one rule when it comes to fast moving geometry or fluid - use more steps per frame. Since your steps are already high enough and if you still are not getting the desired result, think about approaching the setup differently - can’t you attach the simulator to the moving object instead?
I changed the emitter to a slightly simpler object and positioned constrained it to the animated object so it didn’t rotate with it (this was causing some unwanted results).
The sim time is a bit of a killer though, but hey it’s working, so I’m very happy.
1 more question, is it ‘Inscribed’ I should be using for the PFD Properties on the ground plane so the smoke doesn’t float above it?
Yup, inscribed, and also it would be best if the plane is shelled. Also, if you attached the sim to the moving object, maybe it would allow you to reduce the number of steps per frame now?
Inscribed it is, I’ll make sure the to put a shell mod on the plane object. By attached do you mean linked? I have it constrained which is almost the same ( I thought?).
The only work around I have come up with is to set the ground box as excluded and create another collision box underneath this and do several sim tests to get the right height. But I would expect that setting the object to inscribe would work and I must be missing something?.
Oh, this is not the voxel mode - it would have been a matter of less than one voxel above or below.
Does that also show up in the render? Don’t base your conclusions on the viewport previews - they are there to help, but rendering is what matters after all.
Yess, exactly - either exclude the ground box, or make it non-Solid from it’s right click Phoenix properties, and also set the adaptive grid extra margin to 10.
As the grid is moving together with the ball, seems like the adaptive grid first moves, clips the end of the smoke, and just then expands… Please try these settings as a workaround and ping me if it does not look okay.
Seems to be working fine in here..can you send the scene over so we can check it out?
If you don’t need this in the alpha pass - you could add a V-Ray atmosphere render element and it should give you a pass with the smoke, where the geometry will be all black.
Ah, in your case seems that you were misled by the GPU preview. If you go in the Preview rollout of the simulator and turn off the GPU preview, you will notice that the sphere is actually in front of the smoke.
Unfortunately the GPU preview has some limitations for occlusion of objects. You can find more it here - Gpu Preview Occlusion - Common :: Public - Chaos Forum
