Memory problems with displacement

[Numse]

I have had some problems with insufficient memory when rendering with displacement before, but this time it´s for work and I need to check this out and see if there is a solution.

The problem is that all memory gets "eaten" while rendering when using much displacement. I´m rendering seats and using displacement to make small holes in the seat leather, and the irr-map doesn´t even begin to calculate before max shuts down. I have even tried to render the irr-map with no displacement and the render the image with displacement but max/vray can´t handle that either. I have 6 gig of memory now and the scene takes about 1,5 gig. It smells like something is wrong..

I have tried both 2D and 3D displacement.

[vlado]

Which 3dsmax version are you using? 32- or 64-bit? Which V-Ray version? Do you get any error message or 3dsmax always shuts down?

Best regards,
Vlado

[Numse]

Max 9 64 bit. Vray RC3 64 bit. No error message.

[vlado]

In that case increase the dynamic memory limit, e.g. to 2000 MB and see if it makes things better.

Best regards,
Vlado

[visumporec]

I had the same problem with displacement on MAX 9 64-bit, XP-64, 6 gb Ram...
Increase the displacement Edge length parameter from 4 to 8 or 10.
Thats worked for me...

[Numse]

@vlado
I´ll try that. But it still takes AGES to render.

@visumorec
Noo, thats not a good solution. I have such small details in my displacement so I must have 1 or even lower.

[priad]

I have exactly the same problem !!
This make me crazy, I have switched to dynamic and 2000MB seems to work but But it crash after, What we need to do ?
At first it crashed during the end of the lightcache and now during the render, when it reach 1500MB of memory.
Cheers

[priad]

The increase hedge length works but I agree with Numse about the details, displace is good because of the detail.
This must be fixed please.

[vlado]

I have exactly the same problem !!
This make me crazy, I have switched to dynamic and 2000MB seems to work but But it crash after, What we need to do ?
At first it crashed during the end of the lightcache and now during the render, when it reach 1500MB of memory.
Cheers

If you want to use more than 1.5 GB, you need to use a 64-bit 3dsmax/V-Ray. Otherwise there simply isn't enough memory to hold the displacement details. With lower dynamic memory limit, V-Ray will attempt to reuse the memory, but that may slow it down quite a lot. Depending on the particular situation, you might be able to calculate your GI solutions (light cache, irradiance map) with the displacement OFF, save them, and then turn it ON for the final render with using the saved solutions.

Best regards,
Vlado

[priad]

Thanks for the answer Vlado.
I have switch to 7 in edges, and made crop render to arrive to the end.
But that was limit , I understand well your answer and I must take some time to switch to 64.
Thanks for the tips about saved GI, I'll try it.
Regards

[DaForce]

Yeah there is only so much detail and information you can cram into a 32bit file system before stuff jams up

You could also do a few region renders of the scene and just set the last render to remain the same in teh VFB, that way you could redner smaller parts and at the end you would have the full render.
I dont know how that would work with the other channels, diffuse..etc.. but it would certainly work for the RGB channell.

[tricky]

I have just posted a problem that I am having and it could be related. I have a small, but effective amount of displacement on some picture frames in my render. The LC and IRmap calculate OK but it seems to crash when rendering. I am using DR with 64bit machines, 4GB ram, Max9 64bit and Vray 64bit RC3.

The vraydisplacement is set to default values apart from the subdivs are upped to 512 and I have ticked 'use object mtl' and 'keep continuity'. The amount is .04 (I am working in meters).

Any suggestions?