ImportanceSampledEnvironment.html.md 2.1 KB
ImportanceSampledEnvironment
Manages a preprocessed HDR environment map (CDF textures, uniforms) and exposes TSL helpers for BRDF-direction lookups and MIS importance sampling.
Constructor
new ImportanceSampledEnvironment( importanceSampling : boolean )
importanceSampling
When true, builds luminance CDF tables and enables MIS env sampling.
Default is false.
See:
Methods
.sampleEnvironmentBRDF( params : Object ) : Node.
Environment reflection for a screen-space miss using only the BRDF / reflected-ray direction.
params
cameraWorldMatrix
viewReflectDir
View-space GGX-sampled reflected ray.
N
View-space shading normal.
V
View-space direction to camera.
alpha
GGX roughness (alpha).
f0
.sampleEnvironmentMIS( params : Object ) : Node.
Environment reflection for a screen-space miss, estimated with multiple importance sampling (MIS) between the BRDF / reflected-ray direction and the env-luminance CDF direction. Both techniques use consistent solid-angle PDFs (D·G1(N·V)/(4·N·V)), so the power heuristic is unbiased. Adapted from three-gpu-pathtracer.
params
cameraWorldMatrix
viewReflectDir
View-space GGX-sampled reflected ray.
N
View-space shading normal.
V
View-space direction to camera.
alpha
GGX roughness (alpha).
f0
Xi2
Second blue-noise sample (zw used for the CDF).
See:
.sampleReflect( params : Object ) : Node.
Simple environment lookup along the reflected direction (no MIS).
params
cameraWorldMatrix
viewReflectDir
sampleWeight
Optional radiance scale (defaults to 1).
.updateFrom( hdr : Texture )
hdr
Equirectangular HDR environment map.