Vray motion blur + frost: Infinitely builds motion blur accel. and runs out of memory

[joconnell]

Heya Vlado,

I'm doing some blood bits with frost and particle flow at the minute - nothing special at all but I've got one element which keeps building memory until your machine either hangs or goes to virtual memory. It's a simple system with frost and particle flow for non interactive blood in the foreground and background of a shot, and then a realflow element in the centre. To allow better z depth blurring, I'm splitting it into three renders for front, middle and back, but I'm finding with the front element that it'll never render due to the motion blur being stuck at the preparing accelerator stage. The odd thing is that the scene rendered successfully when I had the realflow and the back frost element visible at the same time, but not when I simplify the scene. Would you have any thoughts on what typically would be causing this?

Cheers!

John

[joconnell]

Right - here's something a bit further on this. I was going to clean up the scene as much as possible so I could make a temp scene to mail across. When I tried opening the scene at home it had fume and realflow in it, and it turns out that it was a fume plugin causing the issue. At one point I was using a fume follow op in an earlier version of the scene and there was an object on one of the layers called "FumeFX_PFlow_LinkerDummy001" so that's probably some kind of trash left over from fume - oddly enough it's not showing up in the particle flow window as a "fume fx follow op" to be deleted but it's having some kind of influence on particle flow and stopping everything from rendering.

Try opening the attached scene and hitting render, then try deleting the object on the fume layer and render again. There's a max 2012 file at http://dl.dropbox.com/u/575602/103_2...o_realflow.zip - might be more relevant for Kresimir over in afterworks or the thinkbox frost guys though?

[joconnell]

Right, so found out more about this again and hopefully a permanent solution.

The particle flow was set to render "none" as I didn't want it to produce any geometry - I was using shape operators and scale operators in the flow to control the size of the frost surface so none seemed the correct option. It also worked fine on background particles without any tweaks which is slightly odd. The second odd thing is that "Phantom" mode is supposed to be particle flow's method of calculating particles without having geometry actually produced in the viewports so it should in theory be the best for Vray and the likes of frost - where you want particle flow to make the movement only and frost to supply the final geometry. Using phantom mode with vray seems to produce geometry in the final render so it seems that you need to select the top operator of each particle flow object and manually set it to non renderable.



Edit - spoke too soon, still screwed once it goes to the farm.