Lighting problems: negative lighting’s scuff and vertex shading’s yet to be implemented.

[DarkDruid216]

Describe the project you are working on

I’m working on a mobile turn based tactics game with its graphics in the vein of 5th gen games. I’m looking to use baked lighting for my scenes so the device wouldn’t have to process them on every single frame.
This’s only half of the story. I’m looking to use vertex lighting to cheapen the cost to run the game. I’m also thinking of using subtractive lighting for the likes of exitways, interiors, or certain abilities to have them pop a tad bit more.

Describe the problem or limitation you are having in your project

I see they’ve yet to implement vertex shading.
Meanwhile, negative lighting seems half implemented. It half works as expected, subtracting the lighting from the scene, but it seems to add in other distances.

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

🤷‍♂️
Just finish implementing them?

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

…

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

Not necessarily.

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

Well… they are the core features.

[AThousandShips]

"just finish implementing them" is rude and unhelpful

Are you talking about per vertex lighting in baked lightmaps?

[DarkDruid216]

Real-time lighting.
I was mostly concerned about real time lighting.
I was planning to use mainly pixel-based lighting for my baked lightmaps.
Though, vertex based baked lighting for ambient occlusion would be pretty cool.

my apologies for it sounding rude by the way.

[AThousandShips]

You can already do vertex based lighting? Or what specifically are you looking for?

[DarkDruid216]

Well… I can’t. That’s the entire problem.
I made an entire shader and toggled it to activate “vertex shading.” It doesn’t work because, according to the tooltip, it’s yet to be implemented.

[AThousandShips]

My bad I had forgotten it wasn't available at the moment, but I'm still not sure what this proposal is about?

[DarkDruid216]

Aye. Apologies on my end, as well. 😵‍💫
Either way, no worries. You’re good.
We’ve reached an understanding here.

[AThousandShips]

I don't know what the timeline for implementing vertex lighting for Vulkan, but probably in 4.1

You're good too

[DarkDruid216]

Ah. Sounds like something to keep my eye on, then. Compatibility, by the way. People who don’t have Vulkan are part of my audience! ÙwÓ

[AThousandShips]

The timeline for compatibility is likely a bit slower because it's generally behind the curve compared to Vulkan in terms of completeness

[Calinou]

• Duplicate of Vulkan: Per-vertex shading not working godot#43093.

Regarding the negative lighting issue, are you sure specular lighting isn't messing with the final result? Try setting Specular to 0 when using negative lights. (Note that the Specular property has no effect with DirectionalLight3D in 4.0, but it works with omni and spot lights.)

Though, vertex based baked lighting for ambient occlusion would be pretty cool.

This is already feasible by painting vertex colors in your 3D modeling software, then ensuring the model is exported with vertex colors (and Vertex Color > Use As Albedo is enabled on materials). You can keep relying on per-pixel shading for real-time lighting this way, which is sometimes desired. Using unshaded mode and vertex colors will give you the best performance, but it won't allow real-time lights to light up objects using this unshaded mode + vertex colors.

[DarkDruid216]

well, I tried that, but here’s the results.
If it’s one, it works as expected, but if it’s higher than 1…

[Calinou]

well, I tried that, but here’s the results.
If it’s one, it works as expected, but if it’s higher than 1…

You'll probably need to use a material with a custom shader to clamp lighting values in the light() function. See also #484.

[DarkDruid216]

Think I’ve to do so, as well.