Octo-packed normal vector input ranges wrong

[Neo-Zhixing]

What is the input range for the normal vector in NRD_FrontEnd_PackNormalAndRoughness and NRD_FrontEnd_UnpackNormalAndRoughness?

This line seems to indicate that when NORMAL_ROUGHNESS_ENCODING is RGBA8_UNORM or RGBA16_UNORM, the input range is -1.0 - 1.0. Therefore we convert that into the 0.0 - 1.0 range accepted by the UNORM texture format.

https://github.com/NVIDIAGameWorks/RayTracingDenoiser/blob/c20d25ae223bd3f1deae35cadd9d0912f79f7895/Shaders/Include/NRD.hlsli#L546-L548

However, in the same function, when NORMAL_ROUGHNESS_ENCODING is R10G10B10A2_UNORM, we pass bSigned = false into _NRD_EncodeUnitVector, indicating an input range of 0.0 - 1.0.

https://github.com/NVIDIAGameWorks/RayTracingDenoiser/blob/c20d25ae223bd3f1deae35cadd9d0912f79f7895/Shaders/Include/NRD.hlsli#L538-L542

https://github.com/NVIDIAGameWorks/RayTracingDenoiser/blob/c20d25ae223bd3f1deae35cadd9d0912f79f7895/Shaders/Include/NRD.hlsli#L255

Am I missing anything here? Or is this just a sneaky bug?

[dzhdanNV]

What is the input range for the normal vector in NRD_FrontEnd_PackNormalAndRoughness?

N is world-space normal, so [-1; 1] (unit length).

What is the input range for the normal vector in NRD_FrontEnd_UnpackNormalAndRoughness?

It should not bother you, since normal encoding & Pack tandem make it transparent for you. You just must use texture format defined by enum class NormalEncoding. Each normal encoding variant has the only one texture format and the only one encoding to avoid misunderstanding.

Am I missing anything here? Or is this just a sneaky bug?

No bugs. p.xy = _NRD_EncodeUnitVector( N, false ); says that p.xy stores encoding vector in [0; 1] range, since the underlying storage is UNORM.