Rotational Motion Blur and Overlapping Geometry Samples...

[Dubbie99]

This is annoying.

Lack of MB is one thing that makes me use RT less.

[ecraft]

Any word on the initial issue of stepping in motion blur? This is preventing me from using Vray.

-Eric

[vlado]

I looked at it; initially I did not find anything wrong on the V-Ray side except that the object rotates somewhat too fast for the 3ds Max internal time resolution (3ds Max has only 160 ticks in a frame; they are not enough to sample accurately sub-frame positions for quickly moving objects). I came to the conclusion that we may need to do some internal interpolation between the ticks; hopefully we'll manage to implement this for the next service pack.

Best regards,
Vlado

[ecraft]

It is using real world rotation RPM values. The real world system has a max speed of 395 RPM or 2370 degrees/second (calculated by a conversion tools such as this). And 2370 degrees / 24 frames results in 98.75 degrees/frame or 0.6171875 degrees/tick. So I guess the question is how many degrees/tick is the max to get non-artifacts?

-Eric

[vlado]

So this now fixed for the service pack in December. If you would like to get the fix before that, please email me to vlado@chaosgroup.com

Best regards,
Vlado

[ecraft]

Vlado,
Thank you for looking into this and getting taken care of. I will try it out once I get through the current round of projects.

-Eric

[ecraft]

Just tried it and it does appear to be fixed. Just curious what was done to address the problem?

-Eric

[vlado]

I just changed the internal time values used by V-Ray so that now they are aligned to the actual 3ds Max ticks. Before that, we assumed that the frame is split in equal parts, but because of the 3ds Max ticks imprecision, they were not really equal in 3ds Max time. So now I aligned our internal time intervals to match the length of the actual 3ds Max ones.

Best regards,
Vlado

[ecraft]

Thanks for the info, just happy it is finally working as expected (whether it is technically correct or not).

-Eric

[vlado]

Thanks for the info, just happy it is finally working as expected (whether it is technically correct or not).

It is correct too

Best regards,
Vlado

[Morbid Angel]

Vlado how is this handled in maya? would there be a similar issue there?

[ecraft]

I was referring to the "3ds Max ticks imprecision" statement by my post.

-Eric

[vlado]

Vlado how is this handled in maya? would there be a similar issue there?

No. In Maya, time values are always double-precision floating-point numbers (as opposed to integer ticks like in 3ds Max).

Best regards,
Vlado

[Dariusz Makowski (Dadal)]

IS the fix available in nightly ?

[Dubbie99]

Glad this one is fixed - it's been bugging me for a while.