Barrel distortion NEW SOLUTION MADE!!!

"bluenote" wrote:

"JMF" wrote:

You are missing the hole thing. This "moving Focal point" method is not a ray-tracing thing, its more like dividing the screen in tiny rings and using different camera settings for each.

But how do you want to do that on fragment level? Typically you convert from world coordinates to clip coordinates in the vertex shader and the fragment shader just loops over all pixels of each triangle. Using a different focal point per pixel means that you can no longer just transform the vertices of a triangle globally. And varying the focal point does not result in an affine transformation, so there is not straightforward way to do that with rasterization. There is actually a paper which (iirc) also approaches distortion on the transformation level (so it is similar to your varying focal point) and tries to solve the issues of the non-affine transformation by GPU based tesselation (better read it, I'm not sure if I remember that correctly).