Render time increases during Maya session

[Mark.Lamkin]

Has anyone noticed IPR render times increase over the course of a Maya session? I'm getting good results in 15-20 seconds per frame on my RTX 2080 GPU when I first launch Maya, then the render times steadily increase as I work in IPR mode. Editing materials and light shape attributes doesn't seem to affect render times, but as soon as I start moving around any scene transforms like the camera or objects, the render times jump higher and higher. After a few minutes of working my render times get up to 4-6 minutes per frame for the same scene that was rendering at 15-20 seconds previously, but relaunching Maya drops the render times back down to 15-20 seconds for the same scene. The behavior reminds me of a memory leak.

This seems to be happening regardless of scene complexity. It even happens when I use a large sphere for the environment backdrop, a small sphere sitting on a plane, and a couple area lights.

Any ideas?

[Stephen.Blair]

Can you get an Arnold log for an IPR session?

• In the Arnold Render Settings, set the log verbosity to Info (Diagnostics tab)
• In the Arnold Render View, click View > Full Log.
• Do an IPR session.
• Assuming you are on Windows, the log will be in the Maya Output Window

[Mark.Lamkin]

Thanks for responding, Stephen. Sorry for my delayed reply, but deadlines....

I compiled a test scene with two spheres, three area lights, and a couple high res textures blended and mapped to one of the spheres. I'm attaching your requested render log. MayaArnoldGPU+IPR_RenderLog.txt

[Mark.Lamkin]

I also took screen shots of the IPR session and annotated them with my comments to document what I see on my end.

[Stephen.Blair · Accepted solution]

Can you update to the latest MtoA and Arnold? Right now you are still on Arnold 6.0.0.0

You'll have to update your NVidia driver too.

For the render times, I was hoping for more details in the Arnold log. See the example I attached for a single continuous IPR session.

The log should also show us why CPU memory usage is increasing (that's what is shown on the Arnold Render View status bar)

example_ipr_gpu_arnold_log.txt

[Mark.Lamkin]

Thanks very much for your help and advice, Stephen. I didn't realize I Was running an out-of-date version of Arnold, so I downloaded the most recent MtoA (4.0.3.2 running Arnold Core 6.0.3.1) and the problem appears to be resolved now. I've been running multiple IPR sessions with consistently fast render times and no CPU memory jumps, even while constantly manipulating scene transform nodes.

Problem solved!