Simple reflector test


(Alexmstahl) #1

I am new to Neon, and trying to model a simple reflector. I have a spotlight pointing at a 50% reflective panel, and the Neon viewport renders the light cone bounce off the panel, as expected. Great. But a second spotlight, pointing into a 100% reflective paraboloid, does not reflect light onto the panel… I only see a reflection of the paraboloid itself. Hopefully the screenshot below will clarify my question. Thanks for any assistance!

(Alexmstahl) #2

p.s. I have twiddled many of the material settings, reflector focal point, and light types to no avail. Thanks


Neon doesn’t support light bunces unless you have Brazil installed.
If you have Brazil then you can toggle on Global Illumination and get the result you are after.

But Rhino 6’s Raytraced mode (Cycles) does:


I suppose so @alexmstahl needs a render engine with caustic support.

(Alexmstahl) #5

Thanks @Holo for the quick and helpful reply.


I think Micha is in on a good point as even though Cycles handles the bounced light it doesn’t seem to do so very sientifically. So you should probably get a render engine with real world light algorithms.

Here one parabola is crome and the other is white plaster and the spread is quite similar.
But give it a go and see if it is good enough for you.

(Nathan 'jesterKing' Letwory) #7

The Chrome is clearly more focused, which is visible from the bright spot. But I do agree there could be better light transports. I have been reading up on some techniques that I might try at some point - unless some core Cycles dev beats me to it, of course :wink:


Yeah, it’s both stronger and more focused, but if it is a physically accurate model I do not know. I guess it should be compared to other engines too. Anyway, it’s fabulous to have this in Rhino and I am so glad you decided to not turn light bouncing off by default!


I think, what we see is the light transport of diffuse GI light only. If we want to see an effect like from a torch reflector, than we need the light transport of reflections. I don’t used caustic of Vray yet, only I know it needs to be enabled. Looks like Cycles doesn’t support caustics:

(Nathan 'jesterKing' Letwory) #10

Cycles does some caustics, but as you can see it isn’t sophisticated. I hope to work some day on improved light transports for this. In the meantime one is free to use an engine that already does it well.