invert depth map

[hatrick]

Hi,

Again i'm lost with some "simple"? math. How i can invert a depthmap after rendering? I'm not shure if "invert" is the right term.

The lowest value should become the highest values and vice versa. Something like a LUT?...

Thank you

Lucas

[kgoossens]

Use complement in a vopcop? 1-value

[anim]

if you just want it decreasing with depth instead of increasing just use -1*depthmap

if you want to see normalized (0-1) range then you can use equivalent of fit() function like fit(depthmap, 0, maxdepth, 0, 1)

if you want to see normalized (0-1) range but inverted then it would be fit(depthmap, 0, maxdepth, 1, 0)

if you want to keep the range just flip the values then fit(depthmap, 0, maxdepth, maxdepth, 0)

so in COPs you can directly use Fit VOP within VOP COP2 Filter, maybe even ramp afterwards if that's only for LUT purposes

for equivalent to fit() in nuke you can use Grade node (where black point and white point are source range and will be mapped to 0,1 respectively)

all depends what kind of output you expect, and where you are compositing that, many tools work with real numbers not normalized ones

[hatrick]

hi,

thank you for your detailed answer! ... I comp in nuke... Example... I have relvant pixel values in the depthcahnnel ranging from 9 to 13. I want the pixels with 13 become 9 and vice versa...

Thank you

Lucas

[anim]

in that case it would be Grade node

blackpoint: 9

whitepoint: 13

lift: 13

gain: 9

in this case you will still see the image as white of course, but the values will be correct

Edited July 11, 2013 by anim

[hatrick]

thanks a lot anim!