Point Light Covered by Torch [SOLVED]

[mrrogersmith]

I am taking the course Learn 3D Modelling for Beginners, lecture 2.16 at about 5:26. Grant has a point light inside of his torch which, when sized appropriately, shines lights into the surrounding area. I’ve got a point light set up identically to his, sized up and with a bright enough power, and yet my light does not light the surrounding area as long as the origin is inside of the torch. No matter how bright or how big I make the light, as long as the origin point is inside the torch I can’t get any light from it until I move the origin outside of the torch.

Edit: It appears to work in Cycles, however Grant’s tutorial is using Eevee, which is what I’m using.

[Megane_Wang]

Is rendering configured to cycles? If not, this won’t work.

This is a sample with a semi-transparent box in front of a blue wall and a point light inside the box, in Blender 4.2:

With EVEE:

With Cycles (not fully rendered, but you’ll see the difference):

[mrrogersmith]

Thank you for the response. Grant is using Eevee in the tutorial, so I’d like to understand why he’s able to get it to work.

[Megane_Wang]

Let me check, did he use an emitting material in the torch? I am still not too familiar with Blender 4 (I still used 3 to follow that tutorial).

[mrrogersmith]

Yes, the torch flame is emissive. He’s also got bloom active, which I’ve replaced with a glare node per his solution.

[Megane_Wang]

Yes, I was about to confirm you this. If you use evee and don’t add anything else, you see the emitting material but it does not emit any light rays that are used outside the material. In order to see that light you have placed inside, you have to use cycles. If there is even a bit of the point light outside the torch, you can see a convincing light around the torch; that’s usually enough for this exercise.

This is a part of my dungeon in 4.2 with cycles:

The same with evee:

The most immediate way to show those lights in evee is to move them discreetly out of the torches. It is not perfect, but better:

Other people more familiar with version 4 may have more elegant solutions

[mrrogersmith]

Thank you for the response and the examples. I am still confused, though, why the tutorial shows it working in Eevee. Has there been some change in how lighting works in Eevee since 3.2 (when the tutorial was recorded) which now makes what we see Grant doing impossible in 4.2?

[Megane_Wang]

The tutorial as I followed it just a few months ago was for Blender 3.4. Maybe they have updated it in part for version 4 but not everything?

Overall, cycles uses detailed ray tracing to deal with transparent materials, diffuse materials, dispersion, complex reflections, and so on, while Evee only shows something that can be convincing but is not the same. Even the glare effect you add through Compositing is only an addition that suggests a nice glow but is applied to the finished render, so it is not taken into account as “light” during render (therefore, even though you can use it to get a beautiful glow in some cases, for example, it does not deal with the corresponding obstacles and shadows , because it is “painted” on the final image).

[CoreyKnecht]

In the Material’s settings, have you tried setting Shadow Mode to None? (bottom-right in this cap).

If I remember correctly, that’s what I did in the dungeon section, and a quick test worked for me.

[NP5]

Select the torch.
Go to Material Properties.
Select flame material.
Check Settings > Surface > Backface Culling > Shadow.

I think it is ridiculously opaque and nonsensical, how anyone is supposed to know or find it is a mystery.

[mrrogersmith]

@CoreyKnecht Looks like 4.2 changes that setting per NP5’s response.

@NP5 That did the trick! It’s working now.

Thanks everyone!

[CoreyKnecht]

@NP5

how anyone is supposed to know or find it is a mystery.

It’s very simple: just ask NP5 XD

[NP5]

LOL.

I had forgotten, found the answer.