I’m trying to reproduce Zap’s “workflow” on rendering diffraction effects in refractions using maya (he does it in max).
so this is where I’m right now:
the original render (IOR 2.42)
and the composing:
what did I done yet:
- modeled a brilliant cut and kicked mia_mat with slightly modified (close to zap’s magic) solid glas preset.
- rendered 3 passes with different IORs: 2.39,2.42 and 2.44
- in fusion I extracted the red channel from the 2.44 pass, green channel from the 2.42 pass and the blue channel from the 2.39 pass.
- merged red -> green -> blue in a screen mode.
- a little softglow and highlight
ok. I’ve been told that a jeweller trys to remove the diffraction effect as much as possible. as there’s a huge difference in the effect between zap’s render and mine (his one is much more evident) there might be two reasons:
a) zap’s jeweller was a little off the mark
b) I screwed up - in the case of the way much to low photon energy for sure. have to fix that.
actually, I rendered 6 different IOR passes fron 2.39 to 2.44 by 0.01 steps. but I didn’t manage to add them together to my likin’. I connected them in the order:
magenta -> blue -> cyan -> green -> yellow -> red and 2.39 to 2.44 in screen mode. no, that was not good (it got much toooo bright).
how I colorized the passes?
loader -> colorcorrection node -> adjusted the gain of the appropriate channel to 0.
magenta: green = 0, red and blue = 1
yellow: blue = 0, red and green = 1
cyan: red = 0, green and blue = 1
I would appreciate any hint or idea about that very much. Master Zap? Are you there?
The technique we will be using here is a very low-tech one - we simply render the scene multiple times with slightly different IOR’s, colorize each of the renderings based roughly on the “color” of that wavelength, and combine the result.
what do you mean by “slightly”? 0.01? 0.05?
what wavelength? do you just pic 3 colors between the blue (0,0,255), green (0,255,0) and red (255,0,0)?
and what is your way of combinig the 6 chanel version?
once again - I would be very gratefull for any comment.