Object as lights (size/mass/energy)

Hello, evening :slight_smile:

How do I go about making proper lighting with the use of objects, I mean I have a corridor and I want to make light sources on the wall that would send 75% of the light down and a little bit towards the middle of the corridor and the 25% to go up, to the ceiling. I know that in the future I want to be able to do a real light source, as in the full interior of the object and creating it the same was in real life but that is a long time away, for now I just wanna be able to imitate it somehow.
So in short how would I go about it?

Thank you and take care.

use light probes. The mechanics in your mind are working ok, but with Blender 2.8 you´d better off using lightprobes to calculate the amount of bounce light.

Thanks for the reply :slight_smile:
but the thing is I tried getting into Blender about 11 months ago but I gave up. Mostly because I was so used to Wings3D workflow and shortcuts that most of the time I just had small rage moment and I gave up. Now getting into Blender again but this time I am spending less time and its everyday and it seems to be working… anyway I am not sure or i don’t remember what are “Light probes” .
I just read some wiki but seems to be somehow really short on explanation, something about taking a digital photo of a light source in real life and then placing it on some sphere, really short and not on point (at least that site was) still it seems like Light Probe you mentioned is simply HDRI (might remember it incorrectly) but thats more for environmental light source

By the way is it possible to use some kind of special box/container that would make the rendering in the place i want. I mean I remember using a long time ago software that would send rays into the dark/outside the place i was rendering, it was going for like 250 meters until the software cut them off. Does Blender/Cycles have something automatic or I have to add something like that (still not sure how to go about that)

Light probes are an EEVEE feature, and you probably want cycles.

In cycles you can use Lamps and Emission materials. Between the two you can create any lighting setup imaginable.

Probes are Eevee renderer only, and is based on a precomputed solution to look up light similar to what a game would do. If you switch to Eevee, add an irradience light probe that fills the room, and increase the preview size of the balls, it should be evident what is going on once you bake it.

Back to cycles, which is a path tracer. This works by randomly throwing rays around until they find a light that influence the pixel in question. The point here is random. If you have an external light such as a sun & sky coming in through a window, there are only a few chances that the ray will actually take the path toward the window and examine what’s outside. A light portal (area light with portal enabled) will help guide the ray toward the location where the portal is located, thus increase the chance of finding light. More rays finding a light will reduce noise for same amount of samples. I don’t think there is a cutoff distance. Cutoff distance sounds more like what Eevee’s probes would have.

This is a relatively simple node setup that you can use on a point light to control the color gradient ftom bottom to top:

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Thanks for the replies, still need to find a way to do decent object light source. that spot light is nice, din’t know you could use so many stuff with it, i thought it was only a simple thing that could only have color changed and those other stuff like size and so on.
But probably the thing you showed with that spotlight can help with mesh light source.