Houdini Resources

Updated on June 26  2024



Deborah R. Fowler



Houdini and Redshift Color Management

Posted Dec 5  2021
Mar 7  2024


COLOR MANAGEMENT:

If you want to use ACES then you need to check on Color/LUT/Controls in the output node.

If you use the Reshift Renderview shelf tool Mplay will look "wrong" unless you change it in the render settings:
In the Redshift ROP - go to the tab Output / Post Effects / turn on Color/LUT/Controls for both Mplay and HDR files
However, now your rendered image will look wrong in mplay

If you use the Render View built in to Houdini it will match the output you get if you don't have ACES turned on in your rop nodes.

There are many people having issues as ACES with OCIO files have version issues
https://www.sidefx.com/forum/topic/82544/?page=1#post-354728

Also https://www.sidefx.com/docs/houdini/io/ocio.html

Another excellent article from a practical perspective Toadstorm Nerdblog's An Idiot's Guide to ACES

Here is an example with a render completed in Mantra (far right) and in Redshift (trying to match the shaders and lights) one without ACES set, one with ACES set as described above for comparison.

Here is what is then displayed in mplay - the non-ACES settings (left) and mantra (right) appear correct, the middle one is the Redshift Renderview resulting render to disk displayed in mplay.



A hacky cheat to preview in Houdini is to going into the img context and run it through a gamma node with .45 (or 1/2.2) set - this is not accurate, but give you a better idea of what it will look like in nuke and matches more to what you see in redshift renderview. Ideally, use nuke.

Also note:
Issue : Redshift Windows: Color correction is not correct by default if camera tab missing.
Solution : Add Redshift camera parameters, Go to Color Correction Tab on the camera, switch to raw and then back to Aces to Fix.Thanks to Tim Steele. Additionally something to be aware of:Issue : Windows/Linux: Redshift Houdini 19.5.640 is using ACES 1.0
Nuke only has options for ACES 1.2 and 1.3