I discovered this whilst playing with blender a few minutes ago. I haven’t seen this technique posted here before, but after looking around I did find a youtube video where somebody else has discovered the same last year.
Just thought i’d post it for interest.
Basically - if you add point lights - then wrap them in a cube that has the volume scatter node applied (with the nodegroup as pictured). Set the anisotropy of the volume scatter to 1 and set the density low, then in your light paths - give 1 or 2 volumetric bounces - your point lights become visible, but the volume cube itself is invisible. This is a bit like you used to be able to do with Blender Internal (cant remember what they were called though).
The light path trick there to supress fireflies and there is no compositing here - this is all “in camera”.
That’s pretty clean, nice node trick!
if you just want to see the lights, you can enable visibility for camera:
no nice bloom effect though…
Yeh - it was the bloom effect I was after, without compositing. I think the old BI renderer could do something like this - but I can’t remember what it was called.
You also get a nice desaturation in the centre of the light, with a more saturated glow around it.
Won’t the volumetric meshes show their edges if you add a sun for instance? That could be fixed with light linking if it works with volumetrics though.
Dont know - it may be situational, but it’s a nice solution to have in the bag.
A couple of test renders to show the difference the light path trick makes:
First render is 1000 samples, with just the volume shader.
Second render is 100 samples employing light path trick above.
Volume shader density 0.1, anisotropy 1. No compositing.