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- 3Delight generates light samples that are algorithmically better than both Arnold and RenderMan. In short, for N x effective samples:
- 3Delight Variance ~ 1/Nx
- Arnold Variance ~ 1/sqrt(Nx)
- RenderMan/RIS Variance ~ 1/sqrt(Nx)
- 3Delight is slower to generate these samples. For draft renders (high variance), Arnold is fastest. For final renders (low variance) 3Delight becomes increasingly faster with increasing samples.
- Both Arnold and RenderMan/RIS produce biased images at low sample counts. More specifically: images are darker. 3Delight manages to keep the same energy overall independent on sample counts.
- Arnold, 3Delight and RenderMan/RIS rely on acceleration data structures to sample the geometric area lights. In Arnold and RenderMan, the algorithmic complexity to build those data structures is tied – linearly, as the graph shows – to the number of samples (as well as the complexity of the light). In 3Delight, only to the complexity of the light matters (time to first pixel for 3Delight was 2-3 seconds no matter how many samples there are).