How to distort final rendered image around a spherical region?

I need to distort my final rendered image around a spherical region, so that it looks like everything is being pulled into that region (something like a black hole, as seen in the animation below, taken from wikipedia).

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I think I need some post-processing effects to achive this, but I don’t know how I can specify which region of the image to distort, as the sphere will be moving around the scene. Any help would be appreciated :smiley:

Looks pretty lame when you have to answer your own question, but here it is anyway:

grab the detonator package from the resources section, and assign the provided “HeatDistort” shader to a billboard. Then use any given normal map texture and you should be on your way.