Slow rendering - unloading RAM?

[chrisjacks21]

Hi guys,

I am rendering an animation currently (1920x1080) and render times seemed far more excessive than I expected. After monitoring them a little, I noticed that the lag seems to be to do with unloading RAM. Once all the buckets have finished rendering which takes about 40-50 minutes and before it writes the output files, it hangs for a further 45 minutes and I can see in task manager that the RAM usage reduces down but very very slowly.

I am using V-Ray displacement for water and have a large hdri applied to a VRay dome light (this is only used for reflections though, I am using VRay Sky for GI).

Dynamic memory is set to AUTO and 0MB.

V-Ray 2.40.03
Max 2010
All machines have 32GB RAM, workstations are i7 X990, rendernodes are dual Xeon E5-2680

Any thoughts?

[Dariusz Makowski (Dadal)]

What format are you saving to? Maybe its the amount of passes that's the issue... Strange problem.

Thanks, bye.

[chrisjacks21]

Hi DADAL - I am saving to 16bit EXR and have 7 render elements (3 x multimattes, 2 x AO, reflection and Zdepth)

Thanks

[vlado]

It's probably the displacement, but would it be possible to get me a scene to vlado@chaosgroup.com to see what can be done about it?

Best regards,
Vlado

[chrisjacks21]

It's probably the displacement, but would it be possible to get me a scene to vlado@chaosgroup.com to see what can be done about it?

Best regards,
Vlado

Hi Vlado,

That would be great, the yacht model in the file is using Npower Nurbs - do you have that?? If not I would have to collapse to mesh.

In the meantime, to give you a bit more info about the rendering setup:

- The irradiance was pre-calculated using 'animation prepass' (medium animation) and light cache (single frame) for secondary bounces - displacement was turned off for this pass.
- Rendered frames using 'animation rendering' and secondary bounces set to none and displacement turned back on.

Thanks

[vlado]

That would be great, the yacht model in the file is using Npower Nurbs - do you have that?? If not I would have to collapse to mesh.

We don't have that; it would be best to collapse to a mesh. Thanks!

Best regards,
Vlado