thicknessHeuristic property
How quickly a horizon decays when the march walks past an occluder,
from 0.0 (horizons never decay, thin occluders over-darken) to 1.0
(each farther sample fully replaces the horizon). Small values are
enough. Only used by AmbientOcclusionMethod.groundTruth when
visibilityBitmask is disabled.
Implementation
double thicknessHeuristic = 0.004;