Just getting my feet wet with Mantra but am already battling noise issues.

In the attached render I am already at 10x10 pixel sampling with a .01 Noise Level yet the noise is still unacceptable to me, not to mention a too long render time for such a simple scene!

Other than decreasing my Noise Level value further is there anything else I should try to reduce my noise levels?

To debug with Mantra you often need to export extra image planes and look at each planes contribution. This will help you determine where the noise is actually coming from. Try raising the secondary ray counts for Diffuse Quality, Reflection Quality and Refraction Quality. Drop your pixel samples back down to 4 or 5 then raise diffuse to 3. Also what are your limits set to? You may want to increase the Diffuse Limit, it defaults to 0. I often set limits all to3 or all to 5 bounces only. Generally leave Volume Limit set to 0 unless you do have volumes in your scene.

Hi, This subject peaked my interest so I built a similar scene to experiment and discovered the following which may help.

- Using a single sided geometry area light (intensity 2 on mine), increasing the area light quality helped a lot. I've shown two Mantra renders to show the difference in quality and time by changing from 1 to 8. I've also shown how a single-sided grid area light can reduce noise by a lot for this scene without needing to increase the light sampling quality.

- To eliminate any “fire-flies”, you can try lowering the color limit from 10 to 1. (It worked for me on this particular scene)

- There is quite a significant difference in time when using identical settings and just changing the shader. (see renders)

- I rendered at 720 x 720 pixels to match the height of your reference, the room has 4 walls with the camera inside. (opposed to using clipping)

- These are not examples of noise free renders but to illustrate the differences mentioned above.

hope that helps
Rob

Brilliant. Thanks for sharing this
Another quick comparison rendered in Redshift same resolution

27 seconds! running a Nvidia TitanXP.
Perhaps not a fair comparison as for one, I see my glass sphere is casting no shadow.

I know there are a good many caveats with GPU renderers in general but for simple scenes I can cut my render times down considerably.