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Author Topic: VRay 5 GPU rendering - RAM management from Itoo side  (Read 470 times)

Morne

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VRay 5 GPU rendering - RAM management from Itoo side
« on: July 31, 2020, 12:43:17 PM »
Hi Guys

As you know, GPU rendering has all kinds of constraints. With VRay 5, and ForestPack and Railclone, is there anything I can do to help Forest Objects and Railclone along, to use less ram during rendering, or manage ram better?

For forest, is it worth using VRayProxies as geometry to scatter with ForestPack, or Itoo does its own tricks with ram and it makes no difference in RAM one way or the other if you use mesh vs vrayproxy?

Note, I'm not talking about rendering SPEED here, I'm mainly concerned about reducing ram for GPU rendering


Rokas

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #1 on: July 31, 2020, 01:33:49 PM »
Hi.

There are some advantages and disadvantages to each choice. Proxies would use less RAM but You could loose some FP features.

https://docs.itoosoft.com/kb/forest-pack/should-i-use-meshes-or-proxies-with-forest-in-v-ray
Rokas
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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #2 on: July 31, 2020, 01:49:00 PM »
Please note this guide was written from our experience with the V-Ray standard implementation, but GPU is slightly different.

For GPU renderers (including V-Ray), our plugin just provides a list of the items to the engine, and ChaosGroup does all the instancing and rendering process. We have not control in the renderer, and don't know how it works internally.
I think ChaosGroup would give you more details, and provide some tricks (if any).

Carlos Quintero
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Morne

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #3 on: July 31, 2020, 01:51:01 PM »
Hi.

There are some advantages and disadvantages to each choice. Proxies would use less RAM but You could loose some FP features.

https://docs.itoosoft.com/kb/forest-pack/should-i-use-meshes-or-proxies-with-forest-in-v-ray

So if I used the default presets for a forest object, layered lawns for example, how would I go about converting the source to proxies?
1) Do I unfreeze and unhide the "forest_templates" layer, so I can get a hold of the source meshes
2) Then simply convert them to vray proxies in place and make sure the vray proxy creation mode option "optimize for instancing" is UNTICKED?
3) Would forst then pick up the objects are now proxies, or I would manually need to load it pack into the forest objects as the source geometry?

Rokas

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #4 on: July 31, 2020, 02:00:16 PM »
I will try to do some testing and monitor GPU vram usage to see if there is noticeable improvements of using proxies vs mesh.
Rokas
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Morne

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #5 on: July 31, 2020, 02:10:04 PM »
I will try to do some testing and monitor GPU vram usage to see if there is noticeable improvements of using proxies vs mesh.

Thanks Rokas, looking forward to your results


Rokas

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #6 on: August 06, 2020, 03:25:35 PM »
I did some testing comparing mesh vs vray proxy using vray GPU.

I found no VRAM benefits of using vrayproxy compared to mesh geometry.

What was unexpected for me is that Progressive Rendering used Less VRAM compared to Bucket Modes.
This is just superficial testing in any way not scientific, just my two cents.

Rokas
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Morne

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #7 on: August 13, 2020, 07:51:09 AM »
I did some testing comparing mesh vs vray proxy using vray GPU.

I found no VRAM benefits of using vrayproxy compared to mesh geometry.

What was unexpected for me is that Progressive Rendering used Less VRAM compared to Bucket Modes.
This is just superficial testing in any way not scientific, just my two cents.

Could you share a screenshot of the type of scene you tested please, as well as some figures of your findings? (no matter if they're superficial, it's alwasy useful to see these kinds of things from other people's point of view)


Rokas

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Re: VRay 5 GPU rendering - RAM management from Itoo side
« Reply #8 on: August 13, 2020, 07:59:42 AM »
Sure
I have used 5 relatively high poly trees


I did not saved vRAM usage numbers. There is a screenshot of most interesting data I took (same test repeated 3 times):


This was done with vray 4 (I doubt it would be much different with vray 5). If You have any suggestions how to expand the testing let me know.
I'm looking forward to expand the testing with vray 5 next and if You have any tips or questions to be answered.
« Last Edit: August 13, 2020, 08:03:11 AM by Rokas »
Rokas
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