Pbrt Results

Average Percentage Accurate: 87.2% → 98.9%

Time: 7.1min

Bad Runs: 1/25

Speedup: 2.5×

Output vs Input Accuracy

Each point represents a Herbie run below. Its horizontal position shows initial accuracy, and vertical position shows final accuracy. Points above the line are improved by Herbie.

Accuracy vs Speed

A joint speed-accuracy pareto curve. Accuracy is on the vertical axis, speed is on the horizontal axis. Up and to the right is better. The initial program is shown by the red square.

Test	Start	Result ?	Time
UniformSampleCone, z	99.9%	99.9%	4.3s	»
UniformSampleCone, y	57.5%	98.3%	13.4s	»
UniformSampleCone, x	57.4%	99.0%	16.5s	»
UniformSampleCone 2	98.9%	99.0%	22.5s	»
Trowbridge-Reitz Sample, sample surface normal, cosTheta			2.5min	»
Trowbridge-Reitz Sample, near normal, slope_y	98.3%	98.4%	11.2s	»
Trowbridge-Reitz Sample, near normal, slope_x	99.0%	99.0%	11.2s	»
Sample trimmed logistic on [-pi, pi]	98.9%	99.0%	15.2s	»
Logistic function	99.8%	99.8%	8.4s	»
Logistic distribution	99.6%	99.3%	9.6s	»
Lanczos kernel	97.9%	97.9%	12.6s	»
HairBSDF, sample_f, cosTheta	99.5%	99.5%	9.8s	»
HairBSDF, gamma for a refracted ray	91.8%	97.9%	12.5s	»
HairBSDF, Mp, upper	98.5%	98.7%	11.8s	»
HairBSDF, Mp, lower	99.6%	99.6%	13.9s	»
GTR1 distribution	98.5%	98.6%	10.1s	»
Disney BSSRDF, sample scattering profile, upper	95.8%	98.3%	9.6s	»
Disney BSSRDF, sample scattering profile, lower	61.0%	99.4%	8.8s	»
Disney BSSRDF, PDF of scattering profile	99.6%	99.5%	10.7s	»
Curve intersection, scale width based on ribbon orientation	97.2%	98.8%	13.1s	»
Beckmann Sample, normalization factor	97.8%	98.5%	10.7s	»
Beckmann Sample, near normal, slope_y	58.0%	98.3%	10.6s	»
Beckmann Sample, near normal, slope_x	57.9%	99.0%	9.8s	»
Beckmann Distribution sample, tan2theta, alphax == alphay	55.6%	99.0%	6.5s	»
Beckmann Distribution sample, tan2theta, alphax != alphay, u1 <= 0.5	60.9%	98.3%	14.6s	»