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• RMAN-20906 Fix bug where rect light textures were read incorrectly.
• RMAN-21184 Fix an issue in XPU where light texture maps required absolute paths.
• RMAN-21635 Fix XPU lighting bug where light map saturation/gamma controls did not get updated in an interactive render session.
• Shadow falloff has now been implemented.
• RMAN-21744 Fix bug where XPU & RIS images did not match involving IES profiles.

Integrators

• RMAN-18198 XPU can now switch integrators during an interactive render. The Riley entry points CreateIntegrator, ModifyIntegrator and DeleteIntegrator are now supported.
• RMAN-21401 In XPU, the numLightSamples parameter to PxrPathTracer is now supported.
• Negative Bxdf emission colors are now allowed in XPU (they are no longer clamped to zero).

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• XPU's default verbosity for OSL is now NORMAL instead of VERBOSE. XPU now supports Option "osl" "int verbose" to change this verbosity.
• RMAN-21227 Fixed issues which could cause crashing when interactively editing OSL pattern nodes in a DCC.
• RMAN-21935 An inconsistency between the getattribute() OSL function between XPU and RIS when dealing with array lengths has been fixed.
• RMAN-21283 XPU now has partial support for the utilityPattern parameter in PxrSurface and other shaders. Currently, only a single utilityPattern is currently supported.
• RMAN-21399 The view vector Vn is no longer incorrectly normalized in XPU.
• Implemented "followTopology" and "continuationRayMode" for XPU PxrSurface Burley diffusion ("subsurfaceType" 4).
• Implemented OSL getattribute("context", "reyesGrid", ...) lookup in XPU.
• DeleteDisplacement and DeleteMaterial (from the Riley API) are now implemented in XPU.
• RMAN-21701 The PxrSurface "diffuseExponent" parameter is now implemented in XPU.

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• RMAN-20904 Fix XPU texture filtering for displacement to better match RIS.
• RMAN-18833 The XPU memory requirements of PTex has been greatly reduced, by a factor of almost 4X on complex shots.
• XPU now automatically adjusts the texture and ptexture reserved cache allocation size to be the minimum of the requested texture memory limit option, and the actual size needed to store all the highest mipmap level texture tiles in the scene. In cases where there are very few textures in the scene and the requested texture memory limit has been set very high, this can be a substantial memory reduction.
• RMAN-19353 Some issues in XPU's substitution of <u> and <v> tokens in texture file map names have been addressed.
• RMAN-21751 A bug in XPU causing the texture filter widths on non-quad subdivision faces to be off by a factor of two has been fixed.

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• Fixed live updates for XPU time-to-first metrics.

RIS and XPU

Deep Output

• RMAN-21298 dsview, dtexmerge (now renamed deepmerge), sho, and other auxiliary programs now support DeepEXR files natively. dsview has also received several improvements.

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• RMAN-19096 Improved time to first pixel for scenes with many instances by around 5x to 7x or more in both RIS and XPU.
• RMAN-20963 A precision issue that could lead to self intersection on flat polygons with user normals in the opposite direction of the renderer computed normals has been fixed (both RIS and XPU).
• RMAN-21578 Users can now use namespaced primvars. Primvars which start with the namespaces used by standard Renderman primvars will still be culled (for example
  the ri/grouping/dice/trace namespaces).

Shading

• 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 sss subsurface scattering from the last hit which was previously missing under some circumstances.  And the sss 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.

Statistics

• Support for gRPC for live stats has been eliminated.
• Improved Telemetry Listener output formatting.
• Missing events in the Telemetry Listener are now included.
• The CSV output from the Telemetry Listener is now sorted by time by default. This can be disabled in the configuration with the "sortOutput" option.
• RMAN-21104 : Change listener name separator to '+' to avoid confusion with Windows drive letters. Now if a DCC needs to override the output filename of an existing JsonReport listener it prefixes the filename with "listener_name+"

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• RMAN-21296 Fixed an issue where changing the pixel variance in Solaris had no effect in RIS renders.
• RMAN-20743 Added "raytracebakedisplacement" option for baking. This option helps prevent artifacts when baking using trace() calling patterns, such as PxrDirt and
  PxrOcclusion.
• RMAN-21546 OpenEXR and DeepEXR autocrop can now use any AOV which has alpha as its source. 
• Add two new parameters to the OpenEXR driver: "string asrgbacolorchannel" and "string asrgbaalphachannel". If supplied, these strings automatically force "asrgba" to be 1, and then serve as the actual channels that get converted to "RGB" and "A" instead of "Ci" and "a".

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• RMAN-20729 The scalability of the texture cache when using many threads on RIS has been greatly increased.

Statistics

• The (new stats) memory tracking label for the RIS raytracing component has been renamed from "rman/ris/rrrenderer/..." to "rman/raytracing/..."
• The progress outputs during baking have been improved: they are now more informative about how many objects and baking tasks remain.

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