AlexaLogC in Linearize Pipeline

AlexaLogC in Linearize Pipeline - RV Developer Example Series

In this example, we provide a simple package to automatically enable AlexaLogC in linearize pipeline for EXR images. RV has a GLSL node that will apply standard computation to transform your images from linear to LogC. You can do this manually by toggling the session manager, going to the big plus button, and adding a New node by type -> LinearToAlexaLogC .*

About this series:

Over the years, I’ve made a number of packages for myself, developers looking get get around a roadblock, or to just reproduce/validate a bug.

While the packages in this series aren’t intended to be fully finished forms of art, they all have some sort of value that I’d like to pass along. You will likely find problems, bugs, and/or things that could be optimized, but the purpose here is to share formulas and recipes to help expose what you can do with RV. I hope this series proves valuable, and I encourage you to share your own packages (assuming you have permission to share them to the public).

If you are new to writing RV packages, also check this out: How do I write my first package in RV?

What does this package do?

This package demonstrates how to automatically enable Linear -> LogC conversion for EXR files.

What can we learn from this package?

In this package, you should be able to have the following takeaways:

  • How to manipulate the RV pipeline group.
  • How to query RVLinearizeGroup and RVColorPipelineGroup

The Package

To install this package, go to RV>Preferences>Packages , then click the Add Package... button. Open the package file, choose your install location, and then make sure both check boxes are checked on the package in the list.
Example_Package_AlexaLogCInLinearizePipe-1.0.rvpkg (1.2 KB)

For help on installing packages, check out the package installation portion of the user manual, here

How to Use

After you load the package above, add an EXR file and RV will display it in the LogC space automatically.


Hey thanks for the awesome code snippet! This helps a lot.

I was wondering how you could modify this code to change to AlexaLogC to something else like SLog3? I see there are other nodes like LinearToAlexaLogC, but none for others like SLog3 for example.

Hey Lenny,

If you are shader-minded, you might be able to make your own SLog3 node, but otherwise I think you are in OCIO-land, since RV doesn’t implement the SLog3 as a native color transform. Implementing it as a shader node, however, is exactly what RV devs would be doing anyway (except as an internal node rather than external), so its functionally equivalent.