[Bf-committers] Updating OCIO luts in runtime

[Xavier Thomas]

Hi,

Long time not participating here.

The C-API for OCIO is incomplete and have just the basic stuuf to load a
config and apply transformation but does not permit to edit/add the current
config, colorspaces, LUTs... But the originals C++ and Python API does.
Also since the last version of OCIO (1.0.9, released o github 4 months ago
but not on the official website) the python API supports Pythons 3. So it
is totaly possible, and easy (once blender is compiled with the correct
ocio version) to use OCIO directly form python and modify the config to add
new LUTs and applyt transformations to buffers.

I did a couple of small tests when I was porting OCIO to python 3 and it
was working Ok altought I did not try to modify the config and made Blender
reload it and recheck that the current project's colorspaces are defined. I
only did red only test. But this sould not be much more complicated than
adding python bidings to the appropriate blender functions.

Note that on linux you can easily change the OCIO version to be compiled
for Blender by editing the install_dep.sh script.


2014-01-26 Troy Sobotka <troy.sobotka at gmail.com>

> On Jan 26, 2014 11:10 AM, "tamerlan311" <tamerlan311 at gmail.com> wrote:
>
> > Apply LUT node currently has the following problems:
> > 2) Ignores that blender internally use linear color space, but LUT
> profiles
> > mainly required srgb.
>
> This is incorrect.
>
> LUTs do not require sRGB.
>
> Further, there are many implications of color transforms that are
> important, such as changing the color model of the data to pull a key or
> secondary grade region, etc.
>
> Remaining in a scene linear or display linear model has nothing to do with
> the need for a color transform node. It is an artificial barrier, and an
> OCIO node is an important and welcome addition.
>
> With respect,
> TJS
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at blender.org
> http://lists.blender.org/mailman/listinfo/bf-committers
>