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• Due to an improved string hashing function, the results from the OSL hash() shadeop when applied to strings have changed. Any shaders which depend on this function (including PxrRamp, when using Random Source = "Object Name") may compute significantly different results.
• Fixed a crash when a varying knot-count was used with the OSL spline() shadeop. PRMAN-2868
• OSL gettextureinfo() can now query metadata in textures.  This is limited to only OpenEXR format textures, and will fail if it can't be done at shader JIT-compile time and constant-folded, which means it's largly incompatible with file-name substitution tokens.
• PxrSurface subsurface "continuationRayMode" 2 (and 1) for "subsurfaceType" 0, 2, 3, and 4 now receives subsurface scattering from the last hit which was previously missing under some circumstances.  And the subsurface scattering noise may be reduced.

• The LPE for direct subsurface scattering in RIS has changed from two bounces C<TD3><TD2>L to a single bounce C<TD3>L. However, the commonly used LPE for subsurface scattering -- CD3[DS]*L -- (which includes optional secondary bounces) works as before.

• Reduce fireflies in diffusion subsurface scattering near 90 degree angles -- as on cubes etc.

• UDIM expansion inside <primstr:> texture substitutions are now supported. RMAN-18303

• The PxrRamp pattern now has a more intuitive 0-1 default. RMAN-21815
• Fix PxrColorCorrect Contrast Banding. This will cause a look difference between RenderMan 25 and 26. RMAN-21770
• When LamaHairChiang's "mollification" parameter is on, the three longitudinal roughness values ("ltRoughnessR/TT/TRT") were mollified too much, leading to hair that looked too diffuse.  This has been fixed in both RIS and XPU. PRMAN-2805

• LamaIridescence albedo and normal AOVs now have prefix "Iridescence" -- to be more consistent with the AOVs of other Lama nodes and the PxrSurface iridescence lobe. RMAN-20871

• Lama specular albedo and normal AOVs now have prefix "Specular" -- to be more consistent with the "DiffuseAlbedo" and "DiffuseNormal" names and match PxrSurface AOV names. RMAN-20871

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