To further reduce the variance of the estimated value ofthe rendering equation (see Equation 15), we use quasirandom sampling sequences. Specifically, we use a Sobolsequence [36] with Owens scrambling [30], which gives theprocedural sequence necessary for assigning an arbitrary number of secondary ray samples to each primary ray sample. We then apply Cranley-Patterson rotation [12] to avoidneeding to redraw samples.
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