Created by Richard Lems, modified to support luminance threshold. Posted with permission from Richard Lems.
patreon.com/rilem
From Richard:
A little while ago I made a Construct 3 port of a ‘Gaussian Blur’ GLSL shader I found on Shadertoy (https://www.shadertoy.com/view/Xltfzj). By trial and error I noticed you can make a pretty convincing bloom effect by multiplying this blur with the original image. So I added that option into the effect!
Blursize
Controls the strength of the blur
Bloomvalue
Controls the strength of the bloom, or actually the multiplication factor of the blurred image. When this value is zero, the bloom operation will not be calculated and the effect will just remain blurred.
Note: I haven't done any performance testing on other hardware for this effect. It might turn out to be pretty intensive (pretty common for blurs and such), so be warned.
In any case, I thought it would be cool to share. If it's something that can come in handy for your project, then awesome! :)
v1-1-1: Mikal from the Construct Community Discord added a luminance threshold value to the effect!