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AI Denoiser — Originally developed at Disney Research, in conjunction with Pixar, Walt Disney Animation Studios, and Industrial Light & Magic, the AI Denoiser brings machine learning to denoising.  It maintains sharpness even in the most difficult of scenes, such as those with hair and fur, or those with lots of points-based effects. 
The AI Denoiser will allow you to cut off your renders substantially earlier than before, saving you time on your render farm.

MaterialX Lama improvements — Our partnership with Industrial Light & Magic continues with RenderMan 25.  First introduced in RenderMan 24, MaterialX Lama brings users a component-based and physically plausible shading system for "Layered Materials". 
RenderMan 25 brings improvements in how light interacts between material layers, as well as new iridescence material response.

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