Look at my render here… Notice I have these funny effects where some render buckets appear to not have finished rendering. I have pasted in my mantra settings to the right top and bottom. What is causing these render anomalies?

It looks more like the specular is using tangent normals IIRC. How are the normals and what does this mesh look like?

Do the artifacts show up if you're not using IPR? Also, which version are you using (if older than 16.0.703, can you try the latest daily build and see if the artifacts are still there?)

Hello dlee, I am using version 16.0.633. Rendering with any other mantra node than IPR, and a variety of settings, I still get these anomalies appearing where the render buckets are.

Can you try the latest daily build and see if the anomalies are still there?

I'll ask systems…

Hi, this looks like preview render artefacts to me. Try unchecking Preview on your Render View tab. (Not sure if you've done this via other methods (ie render to disk) and it still shows up)

If you're looking to reduce noise, you may be interested in my recent post. It focuses on indirect_reflect noise which might be useful for your scene. https://www.sidefx.com/forum/topic/51712/ [www.sidefx.com]

Looking at your settings, to reduce noise, I'd recommend looking at the following…

Reduce pixel samples - Combined with the following, you may not need any more than 3 pixel samples. 4 might be a sweet-spot but this may cause an issue which is described in my post. (so 5 might actually be needed)

Reduce Noise level - I usually add a zero out of habit and look at min/max samples if I need to.

Increase reflection quality - You can set this quite high (ie 10) and get better results than increasing pixel samples.

Increase diffuse quality - You probably won't need to set this very high. (ie 2-4)

Decrease your diffuse limit to 1 - Increasing this can give more realistic results but does increase noise and render times, increase gradually if you need to.

Increase Environment light quality - You can reduce direct_reflect noise with less impact on render time than increased pixel samples.

Rob

Robsdesign takes the cake. I feel so stupid. You are absolutely right Rob. Yes, preview render artefacts. Alright, I'll chalk this one up to only having used Houdini for 3 weeks. Sorry folks, nothing to see here.