dForce RockZ Hair will not render in GPU only mode (Iray)

Tirick

I picked this up in the Moriah bundle, but have not had a chance to try it until today. 

https://www.daz3d.com/dforce-rockz-hair-for-genesis-8-females

This looks great in sample images and in regular preview mode, but any attempt to render it is halted after calculating geometry. Any ideas on how to fix this? I only render in GPU mode (I don't allow it to drop to CPU). I have a 6GB card (RTX2060). Most full characters + clothing + sets I can fit without any editing, even with multiple figures (I try to target <4gb vram for a scene). One G8 figure, with no clothing and no set with this hair applied will stop calculations after attempting to determine geometry. Because the Iray engine doesn't report the actual numbers after its VRAM caps out I can't even determine what it is hitting for a limit.

Any thoughts? I don't see anything in the Parameters tab that might effect geometry. What's worse is that it appears to corrupt a figure completely after applying it. Even deleting the hair doesn't remove the geometry rendering resolution issue. I need to completely delete the figure and start over before it renders (minus the hair). 

Thank you,

Tirick

Edit: Yes, I have the most up to date nVidia drivers.

Richard Haseltine

dForce hair can be quite demanding as Iray, at least through DS, does not support true hairs and has to be sent actual geometry for each hair. I would not be surprised at a 6GB card running out of memory - Help>Troubleshooting>View Log File after attempting to render should let you check.

Sevrin

Try setting Line Tesslation to 2 instead of 3.  The hair won't look the same, but will require less memory.

Also, how much system RAM do you have?

Tirick

I have 16 Gb of system RAM, but afaik that is not used when rendering with GPU.

This is the pertinent part of the log I think:

 

2021-04-21 21:24:37.438 Iray [INFO] - IRAY:RENDER ::   1.2   IRAY   rend progr: CUDA device 0 (NVIDIA GeForce RTX 2060): Processing scene...2021-04-21 21:24:38.705 Iray [VERBOSE] - IRAY:RENDER ::   1.6   IRAY   rend stat : Geometry memory consumption: 2.227 GiB (device 0), 0.000 B (host)2021-04-21 21:24:39.230 WARNING: ..\..\..\..\..\src\pluginsource\DzIrayRender\dzneuraymgr.cpp(359): Iray [ERROR] - IRAY:RENDER ::   1.6   IRAY   rend error: Unable to allocate 786.720 MiB from 145.371 MiB of available device memory

I'll try changing the tesslation setting.

thank you!

I should note that MSI Afterburner reports that it idles around 760mb of VRAM used before attempting to render, then it spikes to 5700 or so and halts. 

Tirick

Sevrin said:

Try setting Line Tesslation to 2 instead of 3.  The hair won't look the same, but will require less memory.

Also, how much system RAM do you have?

That did it, thank you!

2021-04-21 21:32:12.229 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Initializing OptiX for CUDA device 02021-04-21 21:32:12.370 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Rendering with 1 device(s):2021-04-21 21:32:12.370 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : 	CUDA device 0 (NVIDIA GeForce RTX 2060)2021-04-21 21:32:12.370 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Rendering...2021-04-21 21:32:12.370 Iray [INFO] - IRAY:RENDER ::   1.2   IRAY   rend progr: CUDA device 0 (NVIDIA GeForce RTX 2060): Processing scene...2021-04-21 21:32:12.647 Iray [VERBOSE] - IRAY:RENDER ::   1.6   IRAY   rend stat : Geometry memory consumption: 782.313 MiB (device 0), 0.000 B (host)2021-04-21 21:32:16.519 Iray [VERBOSE] - IRAY:RENDER ::   1.6   IRAY   rend stat : Texture memory consumption: 276.750 

That is a huge difference in mesh requirements between Tessellation Level 3 and 2.

Even at Level 2 it is lovely looking hair.

Thank you for the help!

Tirick