Is there a way I could create a gradient map in the frame buffer so that I could map the luminance of my render to four values?
black, 33%, 67%, white.
Not sure if LUTs can do this? It?s more of a diagnostic tool and would be good to be able to toggle on off.
I am not quite sure what exactly are you trying to achieve. Could you give us more details and perhaps some examples of the results that you are looking for.
What about using the background image?
I’m after something that will allow me to simplify my images to four values
I was able to do something similar by creating this gradient map in PS and then saving out a LUT to use in the VR frame buffer however there was an issue - I think something to do with the gamma - I had four values but their distribution was not correct. In PS gradient maps don’t work in 32bit and I had created the LUT from a 16bit file PS file. I tried adding/removing a 2.2 curve in PS and saved out multiple LUTS but I was unable to get the same results between the frame buffer and my 16 bit PS file.
So we came up with two ideas of how you could achieve those results:
1. You could use VRayExtraTex render element with Falloff maps set to “Shadow/Light” type. I am attching you a simple test scene.
2. Another way would be to use the VFB Color Corrections - Saturation and Curve(see the screen shots). You could also save the corrections to .cube file (Globals>Save) and load them later as LUT correction.
