The new FFT convolution bloom

[amoser]

@Tim Hobson;707356

With the Convolution Bloom the main thing to keep in mind here is that the kernel image you use is a whole image filter. The hottest (brightest) part of the image should be much brighter than any other part of the image by a lot! The .exr format is good for this kind of contrast. The Convolution Bloom system also expects the hottest (brightest) point of the image to be at the center, so to do this just make a white dot there and the rest of the image substantially less bright. The blurring effect you’re seeing with the other images is because they don’t adhere to this and simply won’t work well. Also for any kernel images you create if you don’t adhere to this you’ll run into the same blurring issue. I made this mistake as well when I initially started using the system.

Huh, so it’s exactly analogous to an audio impulse response used for convolution reverb. That… makes sense on a number of levels.