Visible light bounce

[AlexC]

Hello
I'm trying to replicate the effect of light bouncing of a mirror a bit like in this image below

I tried in Redshift to aim a spotlight at a reflective surface, with an Environment object, but there is no "bounce" of the light beam.
Is there a way to do this?

Thanks!

[Dr. Sassi]

Hi AlexC,

This is not a default option, but it can be faked quickly for flat surface reflections.
There might be setups that require some Compositing afterward.

Also, if the light origin moves, the rig needs more attention; please advise if so. I will look into it.

That said, please have a look here and let me know what works or not.

CV4_2024_drs_24_RSrs_01.c4d
Press play to see it working - RS render view on.

I used some colors to showcase it more clearly.

Cheers

[AlexC]

Thanks Sassi

That is a great idea, but I guess in my case the ideal scenario is that I would have a way to simulate how lights work in "reality", i.e how the reflection would diminish the light's intensity, how reflective surfaces that have irregularities might break up the rays etc.
Your solution is great though, at least to get to a starting point where I can start "shaping" light reflections.

Thank you!

[Dr. Sassi]

Hi AlexC,

Yes, the inverse square fall-off in the example (above) will work, and the loss from reflections is adjustable (Detail Volume), but yes, as mentioned, that is for flat surfaces as in your image.

All of the sharings below are not workable files; they are explanations, demos, or, at best, brainstorming exercises. But I hope it shows clearly that I searched, as I always believe things are changing. I'm not used to answering from memory, as that doesn't work for me and the way I like to support. My credo: Things are constantly changing, and answering from memory will waste people's time.
.

The file below ignores "of course" the angle in angle out reflection rule.
CV4_2024_drs_24_RSrs_11.c4d

I'm not aware of a reflection volume light option that works with reflective surfaces of any shape. Caustic rendering might come to mind, but no Volume Effect (Environment) is created. The example shows clearly, Caustics do not participate in Volume Lighting.
CV4_2024_drs_24_RSrs_21.c4d

I have explored this evening if I could create something with the new Particle system, as they could be seen as Photons. Perhaps my laptop is not powerful enough I leave a sketch below, which is not (!) a usable file: Take it as a brainstorming seed.
CV4_2024_drs_24_RSrs_31.c4d

All the best

[AlexC]

Wow! Thank you Sassi! These are great, I'm going to dive in and explore, I'm sure there are some great tricks to learn!

[Dr. Sassi]

Thank you very much, AlexC.

It might work based on the project's needs and how long it will be visible, but these are not solutions.

My best wishes