View Full Version : Glow using corona

04-17-2015, 07:12 PM
Think I finally got the hang of this, but the threshold doesn't seem to work.

04-18-2015, 07:33 AM
Why does threshold seem to do nothing? If I put any figure other than 0 in, I get no effect.

04-18-2015, 08:13 AM
Corona works fine for me. It may be because the channel you're choosing for the Corona effect is too dim. The Threshold determines how high the chosen channel must get before Corona is applied. Try setting the Luminosity of the filament to 100 or higher and its Diffuse to 0.


04-18-2015, 12:17 PM
No, it does not seem to work with any value higher than 0.

04-19-2015, 12:37 PM
After some experimenting, perhaps you have a Light inside the bulb to cast illumination and shadows from the center of the filament. Corona appears to need the Lens Flare enabled on a Light to perform the glow around the Light. If Lens Flare isn't turned on, Corona adds glow on other illuminated areas above the Input Threshold, but not around the Light.

Here are some screen shots. I'm using V11.6.3. The Input Threshold works as expected.

If what I describe isn't the case in your scene, you may need to post the scene and objects.


04-19-2015, 02:09 PM
corona does not work behind transparency if I recall. you'd need to comp this effect in. lens flares work with proper tracing options enabled. it's been a while since I've tried these things "in camera" though.