Odd rendering issue - random camera rotation

V-Ray V-Ray Common Off-topic
1

We’ve been having this issue quite a bit recently and it’s leaving us pretty much stumped.
Here’s a .gif to show what I mean, these are just 5 frames in sequence from an animation (excuse the quality, early test):

Every now and then, a frame will get rendered as if the camera is rolled to the right slightly, sometimes it goes a little darker too. Then it goes back to normal.

Probably shows up in 1/200 frames, and isnt caused by just one machine - most of our farm has done it at least once now.
Happens with standard cameras and vray cameras, so i dont think it’s anything to do with that.

Anyone seen it or know what causes it?

2

Which V-Ray version are you using?

Best regards,
Vlado

3

how far from 0,0,0 are you?

4

Vlado - Still on SP1, not had long enough downtime to upgrade yet. Was this a known issue?

jacksc02 - The camera is about 2/3metres away… the scene was built from scratch over 0,0,0. Dont get any origin warning either.

5

I’m sure I’ve seen something like this before on another forum. It turned out that some of Max’s animation controllers were better than others at interpolating accurately between keyframes.

Sorry can’t remember any more.

Dan

6

This plus motion blur would probably do it, what controller are you using on the camera?

7

There is no motion blur on the original frames - thats rpf motion blur. It just rotates to the right slightly in that frame.

The only controller is animation in the z axis. The camera starts at the top, and moves down.

8

Hm, ok then, is it a repeatable problem (e.g. the same rotated frame always renders this way)? If yes, then it is an issue with the animation itself.

Best regards,
Vlado

9

Nope - it’s completley random. In that path it happens twice near the end, but i’ve since rendered those frames again and theyre fine. The first time I rendered it for a test it happened once, near the start.

We’ve had it on 4/5 different projects now, and from what we can see there arent any patterns to it occouring. All of our farm machines are exactly the same spec too, they were all bought at the same time.

10

You can try to upgrade to V-Ray SP2 and see if the problem persists; there was a similar issue that was fixed, although from the images above this looks slightly different.

Best regards,
Vlado

11

I’ll let everyone know thats our best lead then… should bump up the priority of an update. What was the similar issue that you fixed?

Is SP3 out anytime within the next couple of months? if so we’d hold off for that.

Thanks for the help!