So it may be related to the fact that I’m trying to use this TOP for a definitely NOT intended purpose, but as I understand it, I should just be able to use the “File Transform” section with a lookup table and if interpolation is set to “nearest” it would not interpolate between values when outputting looked-up values from the file I provide. So if I hand craft a very simple spi3d file that purposefully skips outputting the value 0.5:
load it as a File Transform and choose “nearest” interpolation, it should “posterize” the image similar to Applying Stepping in the Level TOP or Quantization in the Limit TOP.
Instead it just seems to do the same as linear interpolation. AKA showing the warping that using 0.25 and 0.75 would show at 0.33333 and 0.66666:
but not actually choosing the nearest lookup value like I assume it should.
It may be that 3DLUTs in OpenColorIO can not use “nearest” interpolation, or that it was never implemented, cause who would actually do that in film / color grading?
I’m trying to use the OpenColorIO TOP to efficiently map real colors to the MIDI notes that an AKAI APC40MK2 (and any other MIDI controller really) expects to display the closest color and the 3dLUT file I created (that would output a grey pixel at the exact decimal value needed to be sent on the MIDI out CHOP) relies on it choosing the nearest value present in the LUT table and not interpolating between them since the colors in the MIDI map jump around and don’t fade between eachother.
If this is an inherent limitation of OpenColorIO, that’s fine, but I just wanted to make sure this wasn’t a mixup on TD’s side as to it not actually choosing “nearest” when selected and still using “linear”
I do know the menu does SOMEthing, as the image changes when I switch between linear and tetrahedral.
AKAIapc40mk2.zip (807.1 KB)