Iray: Texture Compression and Performance

Richard John S

When it comes to textute compression in the advanced Iray options. Is it better to set these numbers high or low for better performance?

mjc1016

Depends on what you are doing...if you are going for closeups, single model portrait type renders....leave them as big as possible.  Big scenes, with less individual focus on a single mesh,  you can drop them down a lot.

Performance isn't really the reason to mess with them, though...the reason it exists and to change the limits is memory.  By doing so you may be able to squeeze a bit more into the video card's memory (well, I guess keeping a render in GPU mode IS a performance issue).  If the scene is not using the GPU, then the compression settings don't really matter.

Tobor

As Mjc says, the feasture is for memory considerations, not speed. Daz's docs are still fairly non-existent, but Autodesk has some useful additional info on it, related to their implementation of Iray in 3DS::

When on, enables texture compression. Texture compression can reduce texture memory requirements by up to two thirds. The results are better than using textures of reduced size, and usually renderings show little difference from uncompressed renderings unless the original textures are small. Default=off.

If your scene uses small textures and rendering with texture compression shows artifacts—blurring or aliasing—then don't use this option.

Disable compression below

Sets a threshold for textures size. Textures smaller than this size are not compressed. Default=128 (128 x 128 pixels)

Also refer to this:

http://blog.irayrender.com/post/54506874080/saving-on-texture-memory

mjc1016

Tobor said:

As Mjc says, the feasture is for memory considerations, not speed. Daz's docs are still fairly non-existent, but Autodesk has some useful additional info on it, related to their implementation of Iray in 3DS::

Yeah...texture compression schemes that have minimal to no impact on speed are somthing that comes from Nvidia's long gaming history.  They've had that down for years.

pds

Tobor said:

 

If your scene uses small textures and rendering with texture compression shows artifacts—blurring or aliasing—then don't use this option.

I recently ran into this issue and was pulling my hair out trying to figure out why I was getting strange IRay render results with some textures I'd created. The odd thing was that the main texture was a denim weave and it appeared to be fine, but the stitching was blurry intermittently, yet the "shape" of the stitching could be seen. It took me the better part of a day to figure out the problem because the denim weave didn't appear blurry (by comparison at least) and I could see the outline of each stitch. Anyway, I upped the limits on compression and everything was good again.

Padone

In my tests the high compression ratio tends to generate visible artifacts where the texture has "geometric" thin lines, while it works good for "organic" patterns. The medium compression ratio seems to always work fine. So I tend to use 512-2048 thresholds for my scenes.

https://www.daz3d.com/forums/discussion/160336/grainy-lighting-is-there-a-way-to-remedy-this

AndyS

Yes!

I can confirm this.

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