Feature Request - Lower VRAM usage by preprocess textures

[tcheng00]

Hey Guys,

I'm loving Octane, but I'm a bit concerns about the high Vram usage. I paint all my textures in 4k and 8K sizes. Obviously, this takes up a lot of VRAM space. To mitigate that, a lot of rendering programs are automatically preprocessing the textures down to an optimal size and using only certain tiles of the texture that contributes to the final render defined by the camera view. For example, Arnold uses the .tx file format, which allows tiling and quick resizing. Redshift also goes through a preprocessing phase per frame from the camera view to reduce the geometry and texture memory size. Modo suggests we use tiled EXR format to reduce ram usage.

After doing a quick render on similar scenes in both Octane and Redshift, I noticed that Octane is taking over 5-6 Gigabytes of Vram for geo and textures and had to use out-of-core. On Redshift, the geo and textures were reduced down to roughly 1 Gigabyte of Vram and didn't need to use out-of-core technology.

I don't write render engine, and I know that Octane is emphasizing a future of real-time playback with ray tracing, therefore preprocessing textures go against that philosophy. However, for now, I think to make Octane usable for large scenes with large PBR texture sets, it would be beneficial to provide a preprocess system to automatically scale down our texture and geometry optimally to fit into VRAM per frame and from camera view.

I apologize if I get any technical details wrong, but my general request is to reduce VRAM usage and avoid out-of-core to get optimal render times. Thank you.

[nejck]

Sounds a bit like mipmapping which would be useful indeed I'm also using 4k and 8k textures a lot and even with texture compression it gets tricky on bigger scenes where photoscans (3D assets) also eat a lot of VRAM. You can optimize obviously but it would be neat to have some extra options perhaps

[funk]

+1.

I'd like to see tiled EXR support, or some kind of auto mipmapping based on distance to camera.

[tcheng00]

Yeah, it does sound like mip-mapping now that I think about it. I think this should be a high priority, as it will allow us to maximize use of vram before we need out-of-core.

[paride4331]

Hi,
Use the Import settings button in RGB image node to indicate the preferred channel format for loading the image. This is ignored for 8-bit images. You can also use this for selecting the texture bit-depth of High Dynamic Resolution images in Environment textures.
Regards
Paride

[tcheng00]

I'm using the Max Octane Plugin and I don't see an import button. It looks like I can feed it a bitmap and scale it, but that only works for a static image. If I'm zooming in during an animation, It would be a pain to stop every couple of frames and resize all the textures manually.

[paride4331]

I'm using the Max Octane Plugin and I don't see an import button. It looks like I can feed it a bitmap and scale it, but that only works for a static image. If I'm zooming in during an animation, It would be a pain to stop every couple of frames and resize all the textures manually.

Hi,
Channel Format > this indicates the preferred channel format for loading the image. This is ignored for 8-bit images.
Regards
Paride