4 ms·
I am very confident lumen uses raytracing to accumulate global illumination. Notice the delay when light direction changes. No Rays, no GI.
by HellDunkel 5y ago
I am very confident lumen uses raytracing to accumulate global illumination. Notice the delay when light direction changes. No Rays, no GI.
- incrudible 5y agoI've looked it up [1]: Lumen uses ray tracing to solve indirect lighting, but not triangle ray tracing," explains Daniel Wright, technical director of graphics at Epic. "Lumen traces rays against a scene representation consisting of signed distance fields, voxels and height fields. As a result, it requires no special ray tracing hardware. So, it technically does use a kind of raytracing, but not the hardware triangle raytracing that requires DXR. [1] https://www.eurogamer.net/articles/digitalfoundry-2020-unreal-engine-5-playstation-5-tech-demo-analysis https://www.eurogamer.net/articles/digitalfoundry-2020-unrea... Distance-field raytracing isn't a new thing in UE either, they've been using it for shadows and AO for a while.
- HellDunkel 5y agohttps://docs.unrealengine.com/5.0/en-US/RenderingFeatures/Lumen/TechOverview/ https://docs.unrealengine.com/5.0/en-US/RenderingFeatures/Lu... „Lumen uses Software Ray Tracing through Signed Distance Fields by default, but can achieve higher quality on supporting video cards when Hardware Ray Tracing is enabled.“
- HellDunkel 5y ago„ Hardware Ray Tracing also scales up better to higher qualities — it intersects against the actual triangles and has the option to evaluate lighting at the ray hit instead of the lower quality Surface Cache. “