Motion blur issue - specific frames crashing out

[Neilg]

I've been rendering a buildup animation for a job, and while most of it renders fine there are a few frames which crash out no matter what when I have motion blur turned on.

I've attached a stripped down version of a scene which crashes at frame 244, and that frame only. Another one i'm working on has another 3 completley random frames scattered through the path that it wont render - the rest of it renders fine with no issues.


The objects causing the issue are subdivided meshes with an animated slice plane on, and while an error does pop up in the vray dialog box, it flashes up instantly and then max dissapears so I cant even read what it says. Any ideas on what's causing this?


Here's the scene:
http://www.megaupload.com/?d=UVQX8L9E

[Morbid Angel]

so I've picked at your scene. I'd have to say that its a pretty messy scene; a lot of geometry for no reason print overbright warnings even though they seem fine, and if I apply a override material problem still exists. Anyway, I had a success of rendering frame 244 if you remove the HDRI from gi/reflection environment overrides. And your scene renders fine without motion blur, but also since you have changing topology its not motion blurring anyway.

[Neilg]

It's there for a reason in the non-stripped scene, bear in mind I gutted that quickly before uploading...
Also dont get overbright errors here normally, but i'll try what you said now and report back.

As for how messy it is, i've had 2 days to do a full particle flow 1k frame buildup of 5 buildings and a site, with each building having a good 3-4k panels. I've also only done this a couple of times, give me a break...


Edit: I know those objects arent getting motion blurred, but i've done this before with the same technique - a main structure subdivided and a slice plane animated, and motion blur worked fine on that. Another reason this was so confusing.

[Neilg]

Just tried taking the HDRI out of all of the overrides, including the environment slot.

Still crashes. Gets right to the end of the IR map and dies. If I turn the IR map off/render with brute force, it dies shortly after hitting the building.
I know it works without motion blur on, but there are things in that scene normally that need motion blur.

[Morbid Angel]

have you tried considering a 2 pass composite approach? you can render everything else with mb and then comp with the building. Or perhaps use motion vector for post motion blur. Lastly, if you have something like reel smart motion blur you can actually comp motion blur right in post, its not the best, but could get you through this one.

[Neilg]

Thats what I did in the end, it had to be done for this morning - I was just wondering why it actually happened and it seemed like an odd bug to not render one specific frame.

[Morbid Angel]

well it defenently shouldnt crash. So...vlado should look at this.