Consider including support for KHR_lights

[donmccurdy]

Once the draft extension is finalized, it might be worth including support for KHR_lights here.

[dakom]

Cool, by looking at https://learnopengl.com/PBR/Lighting I made more changes to my work-in-progress adaptation

However - I'm still confused how to add the IBL without a directional light. For now I just hardcoded a default value independant of the KHR/Punctual lights.

If someone could take a look at either repo and advise how to calculate the IBL without a directional light, I'd appreciate it!

Thanks :)

[pjcozzi]

@dakom thanks for your effort, I'll ask around if anyone can take a look. Perhaps @emackey, @snagy, or others.

[dakom]

Thanks @pjcozzi !

FYI I deleted and edited some of my questions above to keep the discussion focused on implementing lighting for this reference shader - since I'm seeing some of my questions were kinda basic/general :)

(though if someone happens to know how I can get a direction vector from a light object's transformation matrix or quaternion, independent of position - e.g. for a directional light, I'd love to know... been like 6 hours and I'm still not getting it right hehe)

[snagy]

@dakom None of the light-dependent members of the pbrInputs struct are actually used in the IBL contribution; either using a dummy light vector or writing a new version that just has the view & surface dependent values should do what you want. (just to make sure I'm answering the right question...you want to call getIBLContribution without having a light in the scene, right?)

[dakom]

Oh, @snagy you're 100% right - I missed that NdotV and reflection didn't actually depend on the example directional light at all.

I've updated my adaptation to separate those values out and the IBL works fine without punctual lights.

Thanks!