Release Notes — Version 26.04#

May 2026#

Core Improvements

  • Instant NuRec: Added a new instant_nurec config that allows for faster NuRec training and higher quality output. Generate gaussians with Instant NuRec for input to NuRec to optimize for training speed and quality.

  • Harmonizer: Released Harmonizer, an online diffusion enhancer that improves temporal consistency, appearance harmonization, artifact correction, and lighting realism on neural-reconstruction renderings. Pretrained checkpoints are on Hugging Face (nvidia/Harmonizer). See :doc:Use Harmonizer for Post-Processing <../nurec/harmonizer>.

  • GSplat Renderer — Lidar Rendering: GSplatRenderer now supports lidar rendering, including direct use of gsplat’s own lidar preprocessing and removal of legacy transpose workarounds. Adds antialiased camera mode by default, saturate_radiance support, and sensor-type-specific output configs.

  • GSplat Training Recipes: New car2sim_gsplat and car2sim_6cam_gsplat config YAMLs, plus an end-to-end Waymo-on-gsplat training recipe.

  • Unified gRPC Renderer Selection: New --renderer flag on the gRPC server selects the rendering backend (default for the artifact’s trained renderer, gsplat to force GSplatRenderer, or nrend for the fast C++/CUDA JIT). The legacy --enable-nrend and --use-gsplat flags are deprecated and emit a DeprecationWarning when used.

  • Lidarfree — Colored Ground-Mesh Init: Lidarfree now initializes the road layer from a colored ground mesh, with sparsity compensation, optional random road points, and a clearer projection-type config to disambiguate from the new NRM projection.

  • Lidarfree — Traffic Light Layer: Traffic light layer is now enabled in lidarfree mode.

  • Stateless Track Edits: Track edits applied via the gRPC API and render command are now stateless, simplifying composition with other edits and avoiding cross-request leakage.

  • Demo Transform in Lidar Render: render_lidar requests now apply the demo actor transform consistently with camera rendering.

  • Per-Step Validation Render Directories: New separate_val_dir_per_step config prevents validation renders from being overwritten across training steps.

  • Direct S3 Reading: nvs_ncore and aux_gen can now read scenes / data directly from S3 paths without an intermediate download step.

  • NCore Upgrade: Adopts NCore’s native time-restriction API, exposes cuboid_loading_max_workers (defaulting to serial in V3 to avoid contention), adds caching for loaders and sensors, and enhances cuboid data-processing options.

Bug Fixes

  • Static Rigids Rainbow Artifacts: Reduced rainbow artifacts that appeared on static_rigids layers.

  • NCore Pose Dtypes: Fixed pose dtypes and made world_global optional in NCore loading; extended batch tests.

  • Frame Transform Pose Dtype: Preserved T_poses dtype in frame_transform_pose to avoid silent precision loss.

  • Static Tracks Failure: Fixed an initialization failure path for static tracks.

  • Lidarfree on NCore V4: Removed the hard requirement of a lidar sensor for lidarfree training when migrating to NCore V4.

  • USD Export Track Filtering: Refined track filtering and logging during USD export.

  • Celsius Output Range: Fixed the celsius output range in temperature post-processing.

  • gRPC Lidar Rendering Without Lidar: Returns a clear error message when an artifact has no lidar sensor; up to one lidar sensor is now supported (zero allowed).

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