Release Notes

2020.3 Point Release

Real-Time mode improvements

  • Sampled Lighting mode has improved handling of translucent geometry

  • Fixed bugs with many-light sampling and multi-GPU

  • Reflections now support indirect diffuse GI

  • Indirect diffuse GI works better and faster than before

  • Improvements for DLSS:
    • Updated to a new version of DLSS

    • Fixed bug with some post processing passes not being aware of DLSS, resulting in incorrect results

    • Fixed texture LOD bias to meet the DLSS requirements

    • Fixed DOF flicker artifacts,

    • Fixed reflections to be sharp where they should be sharp

  • Fixed bugs in multi-GPU that resulted in incorrect blending across the large tiles

  • Fixed crashes with Sampled Lighting mode in multi-GPU mode

General improvements

  • AutoExposure now works as expected

  • Fixed issues with handling of metersPerUnit=1 in volume parameters

  • Fixed a bug in how we dealt with the V texture coordinate flipping, which resulted in normal mapping not matching Iray and other issues. The material templates we provide have been updated to preserve the original look for normal maps, but they will now match across renderers meeting the MDL spec.

  • Disable legacy MDL-in-USD schema by default, behind a setting

  • MDL templates we provide, such as OmniPBR, OmniGlass or UsdPreviewSurface now use a new parameter called ‘enable_opacity’, which the RTX renderer can recognize to determined whether cutout_opacity can have values different from 1.0. This is a convention that we rely on to better optimize for this case without duplicating shader code for materials

  • The UE4 material template will now set material.geometry.normal when clear coat is not used. This matches better how the real-time mode currently expects to find normal mapped normal values.

  • Improved code generation from MDL materials to generate less code and compile faster

  • Material Texture parameters stored in USD (as oppose to MDL files) are now correctly accounted for by the progress bar and the path-traced mode (resulting in rendering accumulation resetting as these texture load)

  • Added two new options to reduced GPU memory usage for textures: one (enabled by default) is to use texture block compression at load time, which can reduce texture memory usage to 1/4 of the original. The other option is a user-controllable setting to set a cap on the size of the texture mip levels to keep after mipmap generation.

  • Improved interactivity by decoupling UI/Main loop and Viewport rendering loops, combined with other tweaks to provide the UI rendering more opportunities to run its workload on the GPU as frequently as needed.

  • We can now handle many more skeletal mesh prims without requiring a command line option to increase descriptor set reservation

  • Light and audio guizmos are now rendered as sprites instead of USD prims

  • Selection outline now does not use rasterization, instead using ray tracing to handle large amounts of geometry as efficiently as the renderer

  • Fixed a bug that resulted in Multi-GPU consuming more GPU memory than it should have

  • Startup time reduction by compiling global shaders in parallel

  • Render Settings UI has been rewritten with new UI framework and cleaned up to be simpler and clearer

  • Some Render Settings defaults have changed: DLSS is now enabled by default in Quality mode, Sampled lighting is automatically enabled in scenes with more than a set number of lights (default is 10).

Known issues or limited functionality

  • Rect Light textures only work in Path-Traced mode and with the Sampled Lighting enabled in real-time mode

  • To load USD stages with more than 256,000 instances add this option to your command line: –/rtx/sceneDb/maxInstances=numberOfInstances