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-rw-r--r--drivers/gles2/shaders/scene.glsl103
1 files changed, 70 insertions, 33 deletions
diff --git a/drivers/gles2/shaders/scene.glsl b/drivers/gles2/shaders/scene.glsl
index 958de94485..42b50790b2 100644
--- a/drivers/gles2/shaders/scene.glsl
+++ b/drivers/gles2/shaders/scene.glsl
@@ -898,10 +898,11 @@ varying vec2 uv2_interp;
varying vec3 view_interp;
-vec3 metallic_to_specular_color(float metallic, float specular, vec3 albedo) {
- float dielectric = (0.034 * 2.0) * specular;
- // energy conservation
- return mix(vec3(dielectric), albedo, metallic); // TODO: reference?
+vec3 F0(float metallic, float specular, vec3 albedo) {
+ float dielectric = 0.16 * specular * specular;
+ // use albedo * metallic as colored specular reflectance at 0 angle for metallic materials;
+ // see https://google.github.io/filament/Filament.md.html
+ return mix(vec3(dielectric), albedo, vec3(metallic));
}
/* clang-format off */
@@ -934,6 +935,7 @@ varying highp float dp_clip;
// E. Heitz, "Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs", J. Comp. Graph. Tech. 3 (2) (2014).
// Eqns 71-72 and 85-86 (see also Eqns 43 and 80).
+/*
float G_GGX_2cos(float cos_theta_m, float alpha) {
// Schlick's approximation
// C. Schlick, "An Inexpensive BRDF Model for Physically-based Rendering", Computer Graphics Forum. 13 (3): 233 (1994)
@@ -946,6 +948,15 @@ float G_GGX_2cos(float cos_theta_m, float alpha) {
// float sin2 = (1.0 - cos2);
// return 1.0 / (cos_theta_m + sqrt(cos2 + alpha * alpha * sin2));
}
+*/
+
+// This approximates G_GGX_2cos(cos_theta_l, alpha) * G_GGX_2cos(cos_theta_v, alpha)
+// See Filament docs, Specular G section.
+float V_GGX(float cos_theta_l, float cos_theta_v, float alpha) {
+ float v = cos_theta_l * (cos_theta_v * (1.0 - alpha) + alpha);
+ float l = cos_theta_v * (cos_theta_l * (1.0 - alpha) + alpha);
+ return 0.5 / (v + l);
+}
float D_GGX(float cos_theta_m, float alpha) {
float alpha2 = alpha * alpha;
@@ -953,6 +964,7 @@ float D_GGX(float cos_theta_m, float alpha) {
return alpha2 / (M_PI * d * d);
}
+/*
float G_GGX_anisotropic_2cos(float cos_theta_m, float alpha_x, float alpha_y, float cos_phi, float sin_phi) {
float cos2 = cos_theta_m * cos_theta_m;
float sin2 = (1.0 - cos2);
@@ -960,14 +972,30 @@ float G_GGX_anisotropic_2cos(float cos_theta_m, float alpha_x, float alpha_y, fl
float s_y = alpha_y * sin_phi;
return 1.0 / max(cos_theta_m + sqrt(cos2 + (s_x * s_x + s_y * s_y) * sin2), 0.001);
}
+*/
-float D_GGX_anisotropic(float cos_theta_m, float alpha_x, float alpha_y, float cos_phi, float sin_phi) {
- float cos2 = cos_theta_m * cos_theta_m;
+// This approximates G_GGX_anisotropic_2cos(cos_theta_l, ...) * G_GGX_anisotropic_2cos(cos_theta_v, ...)
+// See Filament docs, Anisotropic specular BRDF section.
+float V_GGX_anisotropic(float alpha_x, float alpha_y, float TdotV, float TdotL, float BdotV, float BdotL, float NdotV, float NdotL) {
+ float Lambda_V = NdotL * length(vec3(alpha_x * TdotV, alpha_y * BdotV, NdotV));
+ float Lambda_L = NdotV * length(vec3(alpha_x * TdotL, alpha_y * BdotL, NdotL));
+ return 0.5 / (Lambda_V + Lambda_L);
+}
+
+float D_GGX_anisotropic(float cos_theta_m, float alpha_x, float alpha_y, float cos_phi, float sin_phi, float NdotH) {
+ float alpha2 = alpha_x * alpha_y;
+ highp vec3 v = vec3(alpha_y * cos_phi, alpha_x * sin_phi, alpha2 * NdotH);
+ highp float v2 = dot(v, v);
+ float w2 = alpha2 / v2;
+ float D = alpha2 * w2 * w2 * (1.0 / M_PI);
+ return D;
+
+ /* float cos2 = cos_theta_m * cos_theta_m;
float sin2 = (1.0 - cos2);
float r_x = cos_phi / alpha_x;
float r_y = sin_phi / alpha_y;
float d = cos2 + sin2 * (r_x * r_x + r_y * r_y);
- return 1.0 / max(M_PI * alpha_x * alpha_y * d * d, 0.001);
+ return 1.0 / max(M_PI * alpha_x * alpha_y * d * d, 0.001); */
}
float SchlickFresnel(float u) {
@@ -996,6 +1024,7 @@ void light_compute(
float specular_blob_intensity,
float roughness,
float metallic,
+ float specular,
float rim,
float rim_tint,
float clearcoat,
@@ -1112,9 +1141,11 @@ LIGHT_SHADER_CODE
if (roughness > 0.0) {
- // D
-
- float specular_brdf_NL;
+#if defined(SPECULAR_SCHLICK_GGX)
+ vec3 specular_brdf_NL = vec3(0.0);
+#else
+ float specular_brdf_NL = 0.0;
+#endif
#if defined(SPECULAR_BLINN)
@@ -1147,7 +1178,6 @@ LIGHT_SHADER_CODE
#elif defined(SPECULAR_DISABLED)
// none..
- specular_brdf_NL = 0.0;
#elif defined(SPECULAR_SCHLICK_GGX)
// shlick+ggx as default
@@ -1157,28 +1187,28 @@ LIGHT_SHADER_CODE
float cLdotH = max(dot(L, H), 0.0);
#if defined(LIGHT_USE_ANISOTROPY)
-
+ float alpha = roughness * roughness;
float aspect = sqrt(1.0 - anisotropy * 0.9);
- float rx = roughness / aspect;
- float ry = roughness * aspect;
- float ax = rx * rx;
- float ay = ry * ry;
- float XdotH = dot(T, H);
- float YdotH = dot(B, H);
- float D = D_GGX_anisotropic(cNdotH, ax, ay, XdotH, YdotH);
- float G = G_GGX_anisotropic_2cos(cNdotL, ax, ay, XdotH, YdotH) * G_GGX_anisotropic_2cos(cNdotV, ax, ay, XdotH, YdotH);
+ float ax = alpha / aspect;
+ float ay = alpha * aspect;
+ //float XdotH = dot(T, H);
+ //float YdotH = dot(B, H);
+ float D = D_GGX_anisotropic(cNdotH, ax, ay, XdotH, YdotH, cNdotH);
+ //float G = G_GGX_anisotropic_2cos(cNdotL, ax, ay, XdotH, YdotH) * G_GGX_anisotropic_2cos(cNdotV, ax, ay, XdotH, YdotH);
+ float G = V_GGX_anisotropic(ax, ay, dot(T, V), dot(T, L), dot(B, V), dot(B, L), cNdotV, cNdotL))
#else
float alpha = roughness * roughness;
float D = D_GGX(cNdotH, alpha);
- float G = G_GGX_2cos(cNdotL, alpha) * G_GGX_2cos(cNdotV, alpha);
+ //float G = G_GGX_2cos(cNdotL, alpha) * G_GGX_2cos(cNdotV, alpha);
+ float G = V_GGX(cNdotL, cNdotV, alpha);
#endif
// F
- //float F0 = 1.0;
- //float cLdotH5 = SchlickFresnel(cLdotH);
- //float F = mix(cLdotH5, 1.0, F0);
+ vec3 f0 = F0(metallic, specular, diffuse_color);
+ float cLdotH5 = SchlickFresnel(cLdotH);
+ vec3 F = mix(vec3(cLdotH5), vec3(1.0), f0);
- specular_brdf_NL = cNdotL * D /* F */ * G;
+ specular_brdf_NL = cNdotL * D * F * G;
#endif
@@ -1197,11 +1227,12 @@ LIGHT_SHADER_CODE
#endif
float Dr = GTR1(cNdotH, mix(.1, .001, clearcoat_gloss));
float Fr = mix(.04, 1.0, cLdotH5);
- float Gr = G_GGX_2cos(cNdotL, .25) * G_GGX_2cos(cNdotV, .25);
+ //float Gr = G_GGX_2cos(cNdotL, .25) * G_GGX_2cos(cNdotV, .25);
+ float Gr = V_GGX(cNdotL, cNdotV, 0.25);
- float specular_brdf_NL = 0.25 * clearcoat * Gr * Fr * Dr * cNdotL;
+ float clearcoat_specular_brdf_NL = 0.25 * clearcoat * Gr * Fr * Dr * cNdotL;
- specular_light += specular_brdf_NL * light_color * specular_blob_intensity * attenuation;
+ specular_light += clearcoat_specular_brdf_NL * light_color * specular_blob_intensity * attenuation;
}
#endif
}
@@ -1290,6 +1321,11 @@ void main() {
float alpha = 1.0;
float side = 1.0;
+ float specular_blob_intensity = 1.0;
+#if defined(SPECULAR_TOON)
+ specular_blob_intensity *= specular * 2.0;
+#endif
+
#if defined(ENABLE_AO)
float ao = 1.0;
float ao_light_affect = 0.0;
@@ -1808,7 +1844,7 @@ FRAGMENT_SHADER_CODE
#ifdef USE_VERTEX_LIGHTING
//vertex lighting
- specular_light += specular_interp * specular * light_att;
+ specular_light += specular_interp * specular_blob_intensity * light_att;
diffuse_light += diffuse_interp * albedo * light_att;
#else
@@ -1823,9 +1859,10 @@ FRAGMENT_SHADER_CODE
light_att,
albedo,
transmission,
- specular * light_specular,
+ specular_blob_intensity * light_specular,
roughness,
metallic,
+ specular,
rim,
rim_tint,
clearcoat,
@@ -1872,10 +1909,10 @@ FRAGMENT_SHADER_CODE
vec4 r = roughness * c0 + c1;
float ndotv = clamp(dot(normal, eye_position), 0.0, 1.0);
float a004 = min(r.x * r.x, exp2(-9.28 * ndotv)) * r.x + r.y;
- vec2 AB = vec2(-1.04, 1.04) * a004 + r.zw;
+ vec2 env = vec2(-1.04, 1.04) * a004 + r.zw;
- vec3 specular_color = metallic_to_specular_color(metallic, specular, albedo);
- specular_light *= AB.x * specular_color + AB.y;
+ vec3 f0 = F0(metallic, specular, albedo);
+ specular_light *= env.x * f0 + env.y;
#endif
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-05 16:12:21 +0000