I leave raytracing sessions leary of using lights ever again. maybe some responses to my confusions below will make the challenges seem more surmountable for me (and others).
1) Copying within a project: When Rhino 7 is behaving well, does using the copy command create an iteration of the original light so that if any copy (or the original) is edited, all the iterations change? When does it, and when doesn’t it? Tutorials have described this behaviour and I have experienced the confusion it can create, but I have also created copies which do not remain linked in that way. I don’t understand how to control and manage this. It seems there are some limitations with copied lights. Is it that they cease to respond to intensity adjustments, though further adjustments are registered on their settings?
2) Copying lights from one project to another: I copied (ctrl+c/v) a set of spotlights from one project to another but they seemed to have negible effect in the new project, despite drastic increases in intensity. New spotlights behaved more as expected. Is there a particular way to copy lights between projects or is it officially (or unofficially) unsupported?
3) Unintended light deletion: Is it just my setup, or does hitting delete to get rid of a number in a light’s intensity input field delete the light altogether from the project for everyone? This has been a shock.
4) “Shadow Intensity”: Help explains it, and I assume that Viewport display settings are applied in addition to each light’s shadow intensity settings. But how is this controlled when Rendering from the Render Panel?
5) A hollowing candle: How to create a facsimile of a burning candle where the wick has burned its way down a cavity into a glowing cylinder of wax? There is a) the glowing candle with a gradient of light scattering through the wax from a hotspot near the flame, b) light from this glow illuminating the immediate environment, and c) light unmediated by the wax going unimpeded directly up and out from the top of the candle.
6) Display colour of an emissive material vs its radiant light colour: How to match them? I find that to get a noticeable amount of (red) light from a material emitting red coloured light, I must turn the intensity of the emissive material’s light so high that the material glows completely white. The red glow it sheds is then unnatural.
I know that Vray is a popular substitute, but so is Enscape - which uses Rhino’s lights.