ImportanceSampledEnvironment

Constructor

new ImportanceSampledEnvironment( importanceSampling : boolean )

importanceSampling

When true, builds luminance CDF tables and enables MIS env sampling.

Default is false.

See:

https://github.com/gkjohnson/three-gpu-pathtracer

Methods

.sampleEnvironmentBRDF( params : Object ) : Node.<vec3>

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.<vec3>

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:

https://github.com/gkjohnson/three-gpu-pathtracer

.sampleReflect( params : Object ) : Node.<vec3>

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.

Source

examples/jsm/tsl/display/ImportanceSampledEnvironment.js