Package limn.render3d

Class IrradianceSh

java.lang.Object

limn.render3d.IrradianceSh

public final class IrradianceSh
extends Object

Order-2 (9-coefficient) spherical-harmonic irradiance baked from an Environment, the diffuse half of image-based lighting (Ramamoorthi & Hanrahan 2001). The environment radiance is projected onto the SH basis over a deterministic Fibonacci-sphere sampling and convolved with the cosine lobe, so evaluate(limn.math.Vec3)(n) gives the average irradiance reaching a surface with normal n (multiply by albedo for diffuse). Deterministic: same input → identical coefficients, so it is unit-testable headless.

Method Summary

Modifier and Type	Method	Description
static IrradianceSh	bake(Environment environment)	Projects an environment into spherical harmonics: done once, not per frame.
static IrradianceSh	bake(Environment environment, int samples)	Bakes with samples deterministic directions (higher = smoother).
Vec3[]	coefficients()	The 9 SH coefficients (for uploading to a shader as vec3[9]).
Vec3	evaluate(Vec3 normal)	Irradiance for a surface normal (clamped non-negative).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

coefficients

public Vec3[] coefficients()

The 9 SH coefficients (for uploading to a shader as vec3[9]).

bake

public static IrradianceSh bake(Environment environment)

Projects an environment into spherical harmonics: done once, not per frame.

bake

public static IrradianceSh bake(Environment environment,
 int samples)

Bakes with samples deterministic directions (higher = smoother).

evaluate

public Vec3 evaluate(Vec3 normal)

Irradiance for a surface normal (clamped non-negative).