Consider adding support for OpenGL ES 3.0 volumetric lights ( see demo ) . . .

[charlesmlamb]

Describe the project you are working on

A barbarian title . . .

Describe the problem or limitation you are having in your project

My problem is, I want say God rays, but at same time SDFGI seems excessive, maybe only want it in say a corridor, or a few places, etc . . . I have no idea if this is dumb, saw a 2 minute video, of OpenGL ES 3.0 volumetric light, already getting volumetric fog, tbc. I DON'T understand what this does, it looks like sort-of turning GI on, for ONE light, I was thinking maybe one could make a performant way, of adding GI here, and there, or so . . . Don't want to use GI, unless it's super - necessary, bec. it can make stuff run slow, etc . . .

Just to be 100 % clear, I don't know what this is, it just looks like sort-of ' local ' sdfgi . . Was thinking that might be quite cool, since I don't need entire scene to be sdfgi, just a few places, where I'd like perhaps god rays, well, it looks nice, in the demo, here's link . . . .

https://www.youtube.com/watch?v=IONAMsLpahg

I guess what I'm asking for, is there any way we can get SDFGI, that is sort of local, or for one light source, so it runs really fast, for making a few windows, instead of something running, for entire scene, that's all . . .

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Well, an option to add local GI, maybe for one light source, or, say a room / area . . Something faster, than normal sdfgi . . . :OO . .

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

Well, saw this amazing demo, not sure what it is, it looks nice, like local GI, very cool . . . .

If this enhancement will not be used often, can it be worked around with a few lines of script?

No, I can't code this, on my own . . . .

I don't know, reason I wanted to ask, is because there's already volumetric fog, not sure, well seems logical to add volumetric light, though I don't know what it is, really would like some local, really fast GI, say for a window, or corridor ( Half-life 2, Resident Evil 5, on PS3 ) . . . .

Is there a reason why this should be core and not an add-on in the asset library?

I have no idea, if one could add fast, performant GI, to a single light source or, area, that'd be amazing and, prob. run on slower hard-ware, demo looks like they have made GI, well, not sure how it's working . . . I don't need full sdfgi, except for AAA titles, be nice with a faster, more optimized system, for making god rays, in a very local space, with neat results, demo makes it look possible, don't understand the tech, behind it, atm . . . :OO . .

[charlesmlamb]

What I'm asking for is maybe not volumetric light, more like, some way to have GI, from one light source or, in a very limited area, and avoid using sdfgi that makes my frame - rate drop, rather a bit, atm . . . . Maybe there's a way to include that, using a limited sdfgi or, not sure . . . . :OO

Sorry, demo just looked rather cool . . . .

It's sort-of what I want, local GI, so on . . At same time, don't really understand tech or, one might make some implementation, using sdfgi, of something close, to this, say a light source, where there's a signed - distance field around light, to make a GI volume, sort-of more localized GI, that'd be nice, esp. if it ran quite fast . . . .

[charlesmlamb]

I'm not an expert, I heard Godot 4 will at some time have OpenGL ES 3.0, this might be dumb, could one bake stuff like GI, I mean god rays, fog, or so . . Guess I'm asking for a more optimized, efficient, local GI system, that would work in OpenGL ES 3.0, if that's possible, something PBR - based or, so . . . So, guess asking for limited, local GI, in OpenGL ES 3.0, something that runs fast on any computer or, to bake PBR god rays, or so . . . The demo just makes it look, well easy . . . Is there a neat way, of doing this, well that'd be nice, esp. for beginners, or so . . . . Well, there are more 3D experts here, maybe there's some nice system, that'd fit Godot, no bull - shit . . .

[Calinou]

There are no plans to add high-end features to the upcoming OpenGL renderer, as all hardware that is fast enough to render volumetric fog supports Vulkan. If your hardware doesn't support Vulkan, then it's better to fake volumetric lighting by using sprites instead. Anything else would be too slow.

As for using the volumetric fog system as a volumetric lighting system, it's technically possible (but not physically accurate) by making fog rendering additive instead of using a mix operation: #1374

Well, an option to add local GI, maybe for one light source, or, say a room / area . . Something faster, than normal sdfgi . . . :OO . .

It's already available in Godot 3.x and master – it's called ReflectionProbe 🙂

[charlesmlamb]

REFLECTION probe, only seen GI probe at GDQuest . . !

I read docs, asap . . . !

[Calinou]

Closing, as this feature is already provided by an add-on for Godot 3.x: https://github.com/SIsilicon/Godot-Volumetrics-Plugin
Using billboarded light sprites to fake volumetric lighting is also an option (even in GLES2).

Godot 4.0 has built-in support for volumetric fog and fog volumes, but it can't be backported to 3.x as it relies heavily on compute shaders.