Moblur and poping objects

[Morbid Angel]

I run into this once before back on vray 1.45 but was unable to reporduce the effect so I left it. Now I get this again and its bad. So, here is the scene which I did for the shot where the ice is breaking and pieces are falling down. All is simulated with reactor. Pritty simple actually. And all looks fine but exept when vray renders its with moblur the objects jump all over the place. Please look into this.
Thanks.

http://funtik.com/dvinnik/preview.avi
http://funtik.com/dvinnik/blur_problem.avi

I have sent a scene to Vlado already, but thought I'd post it here just incase.

[vlado]

Assign a TCB rotation or a Smooth rotation controller to your objects and it will be fine.

This is because the results from EulerXYZ rotation are not very predictable. Your objects do jump between frames (although they look fine on frame boundaries).

Best regards,
Vlado

[Morbid Angel]

but, mental ray/scanline multipass render this fine...How can vray be affected by that.
Hmm...Ok will try that but you know me
oh did I mention the ms theory?

[Geddart]

I had this too with my Project. Switching between FK/IK was the Problem there. I could see the jumping with the camera preview though.
I had it on another occasion yesterday with cloth extension when rendering over backburner. It seemed the hard disk of some nodes were full. (although i'm not a 100% sure it was the reason) Maybe you can check that.

[vlado]

but, mental ray/scanline multipass render this fine...How can vray be affected by that.
Hmm...Ok will try that but you know me
oh did I mention the ms theory?

Set your time format to FRAME:TICKS, scrub the current frame around frame #66 and you will see the objects flying around the scene in the viewport... This shows up in the scanline renderer with multipass motion blur too, so it's definitely not a VRay thing only.

Best regards,
Vlado

[gilicom]

Hi
Which methood did you uese for rendering this animation?
did you used single frame or pre calculate sollution?
Cheers
gili

[Morbid Angel]

gilicom not sure what you mean

[Morbid Angel]

here is how mental ray has rendered the same scene...all looks fine I wonder if thats because it translates everything to its own mr thing.
http://funtik.com/dvinnik/mr_icecollapse.mov

[Morbid Angel]

well as vlado said, by setting the rotation to smooth controller the problem was fixed.
- bug hunt continues

[gilicom]

Hi i mean
if you render this scene with global illumination turn on then you must have set a mode for rendering this scene (single frame,incremental add... etc)
which way did you choose to handle the global illumination when you render a scene with moving objects?

[Morbid Angel]

gilicom - quasi for both bounce...no hassle with setup of ir map or anything like that...just turn the sampling and let it render.

[gilicom]

I've noticed that most of your work is animation with moving objects, do you always use this methood?
what do you mean turn on the sampling?
thx
gili

[Morbid Angel]

yeah we do visual effects for film and so we render large chunks of animations all the time. For this, I found quasi is one of the best solutions. Quasi works on principal of tracing multiple rays. The more rays the less noise there is. But ofcourse render times dramaticly affected. However I found that by rendering with quasi the detalization of gi is much greater then that of irradience map.
Quasi is slow, and especially when itcomes to secondary bounce. So rendering interriors its very heavy.\
Hope that explains it.

[gilicom]

yes it does helps
Thanks for the reply

[Trapezium]

Hey Dmitry,

You may also want to look into QMC with Lightcache for your interiors.

--Jon