Introduction
Cubic Lens Distortion (or undistortion as well) is well known in compositing or any VFX package. Basic Lens Distortion would usually solve the distord plate a the center, but closer you would get to the border of the picture, more the distortion will still there. The Cubic parameter let you control that.
It could also be used to give a “Chromatic Aberration” effect
This shader is based on the Algorithm shared by ssonTech website. This algorithm is used in SynthEyes (matchmove software) and is pretty simple.
Examples
k = -1.0 ; kcube = 0.0
k = -1.0 ; kcube = 0.5
Chromatic Aberration example : k = -0.15 ; kcube = 0.15 || using red distord channel with green and blue undistord channel
Shader (Media Player Classic – HLSL)
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“La Maison” My dream company ^^
Nice tip, I’ll take a look into it
(vous cherchez pas un matchmover par hasard ? )
At “la maison” (vfx company in Paris/Saint-Cloud) a Softimage XSI/Mental Ray shader has been developed to apply lens distortion from 3D Equalizer’s data. The name’s lmWarpDistort.
It’s open source (GNU LGPL license), so it may interest you: http://bitbucket.org/lamaison/lmwarpdistort/wiki/Home