EEVEE-Next: Make light clamping consistent #120866

Clément Foucault · 2024-04-20T23:30:30+02:00

Clément Foucault commented

2024-04-20 23:30:30 +02:00

This adds clamping at the light combine stage for both direct
and indirect light.

This allows for clamping direct and indirect light separately.
While direct light clamping might not be very desirable in
EEVEE, it might be wanted to reduce the flickering from distant
shiny bumpy surfaces, or for artistic reason.

This happens after applying the BSDF throughput just like cycles.
This is done in order to minimize the performance impact and
allows to split the clamp for direct light and indirect light.

The indirect light clamp value is still used in the ray-tracing
pipeline to clamp the ray intensity. But this differs from cycles
as we clamp the ray without the BSDF throughput here. Sphere probe
have the same issues. Some more energy loss is expected compared
to the direct light clamp.

Note that we still clamp the indirect light after applying BSDF
in case the BSDF is scaling the energy up above the threshold.

This also corrects the clamping for volume that now clamps after
applying the scattering term.

Also adds clamping to volume indirect lighting.

Since we use light probe volumes for both surface and volume
indirect lighting, we need to clamp them at sampling time.

TODO:

Make raytraced refraction use the unclamped version of the screen radiance below.
Make fast deferred path output separate indirect radiance if needed.
Add spherical harmonic clamping
Fix missing lightprobe update

This adds clamping at the light combine stage for both direct and indirect light. This allows for clamping direct and indirect light separately. While direct light clamping might not be very desirable in EEVEE, it might be wanted to reduce the flickering from distant shiny bumpy surfaces, or for artistic reason. ![Capture d’écran 2024-04-20 à 23.28.16.png](/attachments/30ac5240-ddd0-48ab-80f1-df9602676575) This happens after applying the BSDF throughput just like cycles. This is done in order to minimize the performance impact and allows to split the clamp for direct light and indirect light. The indirect light clamp value is still used in the ray-tracing pipeline to clamp the ray intensity. But this differs from cycles as we clamp the ray without the BSDF throughput here. Sphere probe have the same issues. Some more energy loss is expected compared to the direct light clamp. Note that we still clamp the indirect light after applying BSDF in case the BSDF is scaling the energy up above the threshold. This also corrects the clamping for volume that now clamps after applying the scattering term. Also adds clamping to volume indirect lighting. Since we use light probe volumes for both surface and volume indirect lighting, we need to clamp them at sampling time. #### TODO: - [x] Make raytraced refraction use the unclamped version of the screen radiance below. - [x] Make fast deferred path output separate indirect radiance if needed. - [x] Add spherical harmonic clamping - [x] Fix missing lightprobe update

Capture d’écran 2024-04-20 à 23.28.16.png

1.1 MiB

Clément Foucault added this to the 4.2 LTS milestone 2024-04-20 23:30:30 +02:00

Clément Foucault added the

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EEVEE-Next: Make light clamping consistent #120866

TODO: