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Fix SH lightmap coefficients for direct lights

This commit is contained in:
Rudolph Bester 2025-02-22 09:38:18 +02:00
parent 394508d26d
commit 8a78d833ce
2 changed files with 41 additions and 32 deletions
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51
modules/lightmapper_rd/lm_compute.glsl
View File

@ -861,15 +861,20 @@ void main() {
light_for_texture += light;
#ifdef USE_SH_LIGHTMAPS
// These coefficients include the factored out SH evaluation, diffuse convolution, and final application, as well as the BRDF 1/PI and the spherical monte carlo factor.
// LO: 1/(2*sqrtPI) * 1/(2*sqrtPI) * PI * PI * 1/PI = 0.25
// L1: sqrt(3/(4*pi)) * sqrt(3/(4*pi)) * (PI*2/3) * (2 * PI) * 1/PI = 1.0
// Note: This only works because we aren't scaling, rotating, or combing harmonics, we are just directing applying them in the shader.
// Since we don't want to double attenuate the light we need to undo attenuation based on the surface
// normal before encoding it into SH coefficients
if (dot(normal, light_dir) <= 0.0001) {
continue;
}
light /= max(0.0, dot(normal, light_dir));
// Different coefficients are used because we are directly encoding point lights.
// L0: Zero is used since the lighting should be able to attenuate to zero (at 90 degrees)
// L1: 1 is to no increase or decrease the lights intensity. This should match dynamic lighting.
float c[4] = float[](
0.25, //l0
0, //l0
light_dir.y, //l1n1
light_dir.z, //l1n0
light_dir.z, //l1n0 (Should always be positive)
light_dir.x //l1p1
);
@ -1253,26 +1258,26 @@ void main() {
#endif
#ifdef MODE_PACK_L1_COEFFS
vec4 base_coeff = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice * 4), 0);
vec4 c = vec4(0, 0, 0, 0);
for (int i = 1; i < 4; i++) {
vec4 c = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice * 4 + i), 0);
// Using the logistic sigmoid function to compress the L1 between 0 and 1
//l1n1
c = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice * 4 + 1), 0);
c.rgb = 1 / (1 + exp(-c.rgb * 4.0));
c.rgb = clamp(c.rgb, vec3(0.0), vec3(1.0));
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice * 4 + 1), c);
if (abs(base_coeff.r) > 0.0) {
c.r /= (base_coeff.r * 8);
}
//l1n0
c = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice * 4 + 2), 0);
c.rgb = 1 / (1 + exp(-c.rgb * 4.0));
c.rgb = clamp(c.rgb, vec3(0.0), vec3(1.0));
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice * 4 + 2), c);
if (abs(base_coeff.g) > 0.0) {
c.g /= (base_coeff.g * 8);
}
//l1n1
c = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice * 4 + 3), 0);
c.rgb = 1 / (1 + exp(-c.rgb * 4.0));
c.rgb = clamp(c.rgb, vec3(0.0), vec3(1.0));
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice * 4 + 3), c);
if (abs(base_coeff.b) > 0.0) {
c.b /= (base_coeff.b * 8);
}
c.rgb += vec3(0.5);
c.rgb = clamp(c.rgb, vec3(0.0), vec3(1.0));
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice * 4 + i), c);
}
#endif
}

22
servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl
View File

@ -1690,23 +1690,27 @@ void fragment_shader(in SceneData scene_data) {
if (sc_use_lightmap_bicubic_filter()) {
lm_light_l0 = textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 0.0), lightmaps.data[ofs].light_texture_size).rgb;
lm_light_l1n1 = (textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 1.0), lightmaps.data[ofs].light_texture_size).rgb - vec3(0.5)) * 2.0;
lm_light_l1_0 = (textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 2.0), lightmaps.data[ofs].light_texture_size).rgb - vec3(0.5)) * 2.0;
lm_light_l1p1 = (textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 3.0), lightmaps.data[ofs].light_texture_size).rgb - vec3(0.5)) * 2.0;
lm_light_l1n1 = textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 1.0), lightmaps.data[ofs].light_texture_size).rgb;
lm_light_l1_0 = textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 2.0), lightmaps.data[ofs].light_texture_size).rgb;
lm_light_l1p1 = textureArray_bicubic(lightmap_textures[ofs], uvw + vec3(0.0, 0.0, 3.0), lightmaps.data[ofs].light_texture_size).rgb;
} else {
lm_light_l0 = textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 0.0), 0.0).rgb;
lm_light_l1n1 = (textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 1.0), 0.0).rgb - vec3(0.5)) * 2.0;
lm_light_l1_0 = (textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 2.0), 0.0).rgb - vec3(0.5)) * 2.0;
lm_light_l1p1 = (textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 3.0), 0.0).rgb - vec3(0.5)) * 2.0;
lm_light_l1n1 = textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 1.0), 0.0).rgb;
lm_light_l1_0 = textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 2.0), 0.0).rgb;
lm_light_l1p1 = textureLod(sampler2DArray(lightmap_textures[ofs], SAMPLER_LINEAR_CLAMP), uvw + vec3(0.0, 0.0, 3.0), 0.0).rgb;
}
// Undoing sigmoid function packing
lm_light_l1n1 = -log((1.0 / lm_light_l1n1) - 1) / 5.0;
lm_light_l1_0 = -log((1.0 / lm_light_l1_0) - 1) / 5.0;
lm_light_l1p1 = -log((1.0 / lm_light_l1p1) - 1) / 5.0;
vec3 n = normalize(lightmaps.data[ofs].normal_xform * normal);
float en = lightmaps.data[ofs].exposure_normalization;
ambient_light += lm_light_l0 * en;
ambient_light += lm_light_l1n1 * n.y * (lm_light_l0 * en * 4.0);
ambient_light += lm_light_l1_0 * n.z * (lm_light_l0 * en * 4.0);
ambient_light += lm_light_l1p1 * n.x * (lm_light_l0 * en * 4.0);
ambient_light += lm_light_l1n1 * n.y * en;
ambient_light += lm_light_l1_0 * n.z * en;
ambient_light += lm_light_l1p1 * n.x * en;
} else {
if (sc_use_lightmap_bicubic_filter()) {