New rendering specialised noise reduction: Altus



As you can see, this rendering specialized denoiser looks promising. There is a free demo for the standalone version, but it needs several passes:

The required AOVs are as follows:
RGB: This is the beauty render
ALB: This is an albedo AOV, unshaded texture AOV
VIS: This is the visibility of the geometry to the lights, a suitable AOV for this would be a
shadow AOV
NOR: Forward Facing Normals with bump map preservation
POS: World Position
CAU: Caustics AOV

unshaded textures can be done by changing all shaders to emission shader of intensity 1, so the 4 first pass they mention can be made easily with Cycles, but what about the 2 last? Has someone ideas on how to make it?

Position should be trivial, it’s one of the basic variables you can access in OSL (though I have no idea what happens for transparent or refractive surfaces). And for caustics you just need to add up Transmission Indirect and Glossy Indirect, which are already supported passes in Cycles.

POS can be made using the Geometry node’s “Position” output to an emission shader. I think that is in world space. Not sure about caustics, but, if the scene does not use caustics, this shouldn’t be a problem.

It looks very promissing. I wonder how much will this cost…

They almost never work as good as advertised

I’ll wait untill someone makes a low quality 480p recording with a really bad microphone uses it :slight_smile:

Thanks for the tips guys, it works with what you said for position and caustics.
Here are the results on a simple scene:
With 2x 10 samples given to altus:



with 20 samples


For those wanting to try, you have to save in exr format and edit the altus.cfg file to give the path to the different passes you saved. A script to automate it shouldn’t be so hard.

That’s great, but there are still some big artifacts between lights and shadows.

IDK. PRMan’s NR works pretty well, so clearly with the right data noise reduction is possible.

Yep, but I did it with only 20 samples (2x10) and in a scene that has low complexity. It can sound as it should be easier for the algorithm, but in a real scene, you wouldn’t notice those artifacts that much, because the overall detail would reduce the “detail level contrast” if you see what I mean. Feel free to test this on a more complex scene and post renders :slight_smile:

I think the denoising looks pretty good. Here some additional links:

http://forums.chaosgroup.com/showthread.php?84980-Altus-denoiser

I think that the results are great. It can’t do miracles if the noise is too strong but it works really well when the noise is only subtle.

smooth, shiny surfaces… i can denoise stuff like that myself. show me denoiser with very detailed textures that works.