NVIDIA speeds up RTXPT and adds Windows on Arm support

NVIDIA has released version 1.9.0 of RTX Path Tracing (RTXPT) on GitHub, claiming roughly 20% better performance than the previous 1.8.1 release with comparable or better image quality. The open-source code sample gives developers a starting point for building a path tracer and a reference for NVIDIA’s other ray tracing SDKs.

The update optionally traces only three quarters, half, or a quarter of the pixels each frame. Built-in performance presets enable this behavior by default, with faster modes also using lower bounce limits. On DirectX 12, asynchronous compute allows the previous frame’s DLSS Ray Reconstruction and post-processing to overlap with the next frame’s path tracing. TLAS instance generation has also moved to the GPU.

NEE-AT light sampling now supports up to 2 million lights, up from 512K. The SHaRC radiance cache is enabled by default in real-time mode, apparently supplying more indirect lighting to DLSS Ray Reconstruction at about the same cost. The release also adds Windows on ARM64 support.