Pflow crash with Motionblur and Lightcache

[katho3d]

Hello vlado,

I cant´t render a pflow system with motionblur and lightcache, without crashing max. It´s easy to reproduce:
Create a standard pflow system, turn on "Motion blur", set the "Geometry samples" to 5 (this is important, with 2 it works correctly), turn on GI and set the primary or secondary engine to "Light cache". Now render the perspective view at frame 10... Crash.
Vray version is 2.10.01 Advanced
Could you please take a look at this problem. Thanks!

[joconnell]

Generally it's something to do with particles being created halfway between frames so vray is trying to calculate motion blur out of nothing. You can try getting pflow to calculate more sub frames with it's interval step to feed vray more information - generally you match your vray samples to your pflow ones so if you want to use 5 motion blur samples, you'd have to up your pflow integration step to about 1/8 frame.

[Dubbie99]

It shouldn't crash though, it should either render anyway maybe leaving out those particles, or notify the user of the problem.

[katho3d]

Thanks joconnell, but I already tried many different combinations of integration steps (even 1 tick) and mb samples. It always crashes when I use LC or IR for GI. I figured out that it has something to do with the particle birth (change of vertex count), but there is no workaround for this.

[joconnell]

Is brute force and lc a possibility? As far as I know Vlado had to do some really silly hacks to get pflow to behave - autodesk let the developer of it go almost immediately after they integrated pflow in version 5 so it's likely not the most ideal interface to pass on to a render - as far as I know vray has to recreate the entire mesh from scratch rather than getting passed clean details from pflow.

[vlado]

Can you tell me which 3ds Max version is this?

Best regards,
Vlado

[katho3d]

Is brute force and lc a possibility? As far as I know Vlado had to do some really silly hacks to get pflow to behave - autodesk let the developer of it go almost immediately after they integrated pflow in version 5 so it's likely not the most ideal interface to pass on to a render - as far as I know vray has to recreate the entire mesh from scratch rather than getting passed clean details from pflow.

No, BF/LC or other way around doesn´t work. BF/BF works, but is obviously very slow and/or noisy.

Can you tell me which 3ds Max version is this?

Best regards,
Vlado

Max2011 64bit and Max2012 64bit, both are crashing instantly when LC or IR calculation starts.

[vlado]

Right; this is already fixed in our internal builds, as it turned out. If you would like to get the fix, please email me to vlado@chaosgroup.com

Best regards,
Vlado

[joconnell]

That sounds like a useful one Vlado - what's the schedule like for the next release? As an aside will the option to save scanline exr and embed data window also be included?

[vlado]

That sounds like a useful one Vlado - what's the schedule like for the next release?

There is a service pack coming out in the autumn - most likely around November.

As an aside will the option to save scanline exr and embed data window also be included?

Yes.

Best regards,
Vlado

[joconnell]

Super - great to hear!

[katho3d]

Right; this is already fixed in our internal builds, as it turned out. If you would like to get the fix, please email me to vlado@chaosgroup.com

Best regards,
Vlado

Thanks Vlado, mail sent!

[PsychoSilence]

Don't mean to hijack the thread but I'm experiencing crashes with pflow and MBlur as well. Even with equal mblur setting (1/4 frame in pflow, 4 samples in vray).
I lowered the max tree depth to 50
leaf size is 10
face coef is 2
memory is set to static and 24gig

I figured it is the reflection of the other geo reflecting a crap load of particles...The error doesnt occur when reflections are off in the material of the stage geo (stuff that mattes out the particles.)

[Dubbie99]

By accident, we discovered that machines with Box#2 and #3 crash on our farm, where stock Pflow doesn't crash with the same scenes.

This is possibly relevant to you Ansi.

I haven't had time to investigate more fully.

[vlado]

Don't mean to hijack the thread but I'm experiencing crashes with pflow and MBlur as well. Even with equal mblur setting (1/4 frame in pflow, 4 samples in vray).
I lowered the max tree depth to 50
leaf size is 10
face coef is 2
memory is set to static and 24gig

I figured it is the reflection of the other geo reflecting a crap load of particles...The error doesnt occur when reflections are off in the material of the stage geo (stuff that mattes out the particles.)

If you have a scene that we can debug, it will be helpful...

Best regards,
Vlado