Reflection Not Consistent With Source

Support Materials and Textures
#1

weird-reflection
weird-reflection.PNG713×378 310 KB

In my scene I have a light fixture with three bulbs, each of which is surrounded by a glass globe. The material on the bulb is an emission shader with a strength of 1.0, so they’re not letting off much light at all. The brightness itself is coming from three point lights positioned just behind each bulb, outside the glass globes.

The weird part is the reflection on the shower glass to the right of the image. You can see each bulb, and each glass globe, but it also looks like you can see each point light behind each bulb (the white discs of light between the fixture and the wall). Why would the point lights themselves be invisible where the camera is looking directly at them, but appear as round balls of light in the reflection?

#2

Lamp based lights are camera invisible. The camera visibility checkbox does nothing.

1 Like
#3

What are you talking about? That doesn’t actually answer my question…

#4

You can turn off the setting that makes lights visible to glossy in the object->cycles_settings->ray_visibility of the point lights.
https://docs.blender.org/manual/en/latest/render/cycles/settings/objects/object_data.html#cycles-settings
It’s with this setting by default because highlights from Glossy shaders really need to have a visible light.

#5

Sweet, I just tried that out and it looks like that solved my problem! Which I’m really glad about, because at first I was using the emission shader on the actual light bulb for the lighting, and for some reason that was introducing a bunch of noise into the scene, hence the “fake” point light approach I’m taking now. Thanks for the tip!

#6

The noise is because shadow rays get blocked by all glass materials, and incoming light comes only from refracted rays… This can be fixed by making all glass materials to behave as a TransparentBsdf for shadow_rays.
You can turn the shadow option off in the ray_visibiliy settings for glass objects, or
use Light_Path -> is_shadow_ray to MixShader the GlassBsdf and a TransparentBsdf if you want a bit tinting on the glass shadow.