diff options
Diffstat (limited to 'drivers/gles2/shaders/scene.glsl')
| -rw-r--r-- | drivers/gles2/shaders/scene.glsl | 75 |
1 files changed, 53 insertions, 22 deletions
diff --git a/drivers/gles2/shaders/scene.glsl b/drivers/gles2/shaders/scene.glsl index b1a668cc07..f84f3367f8 100644 --- a/drivers/gles2/shaders/scene.glsl +++ b/drivers/gles2/shaders/scene.glsl @@ -934,6 +934,7 @@ 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 +947,15 @@ 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 +963,7 @@ 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 +971,30 @@ 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) { @@ -1113,7 +1140,11 @@ LIGHT_SHADER_CODE if (roughness > 0.0) { - // D +#if defined(SPECULAR_SCHLICK_GGX) + vec3 specular_brdf_NL = vec3(0.0); +#else + float specular_brdf_NL = 0.0; +#endif #if defined(SPECULAR_BLINN) @@ -1125,7 +1156,7 @@ LIGHT_SHADER_CODE float shininess = exp2(15.0 * (1.0 - roughness) + 1.0) * 0.25; float blinn = pow(cNdotH, shininess); blinn *= (shininess + 8.0) / (8.0 * 3.141592654); - float specular_brdf_NL = (blinn) / max(4.0 * cNdotV * cNdotL, 0.75); + specular_brdf_NL = (blinn) / max(4.0 * cNdotV * cNdotL, 0.75); #elif defined(SPECULAR_PHONG) @@ -1134,7 +1165,7 @@ LIGHT_SHADER_CODE float shininess = exp2(15.0 * (1.0 - roughness) + 1.0) * 0.25; float phong = pow(cRdotV, shininess); phong *= (shininess + 8.0) / (8.0 * 3.141592654); - float specular_brdf_NL = (phong) / max(4.0 * cNdotV * cNdotL, 0.75); + specular_brdf_NL = (phong) / max(4.0 * cNdotV * cNdotL, 0.75); #elif defined(SPECULAR_TOON) @@ -1142,11 +1173,10 @@ LIGHT_SHADER_CODE float RdotV = dot(R, V); float mid = 1.0 - roughness; mid *= mid; - float specular_brdf_NL = smoothstep(mid - roughness * 0.5, mid + roughness * 0.5, RdotV) * mid; + specular_brdf_NL = smoothstep(mid - roughness * 0.5, mid + roughness * 0.5, RdotV) * mid; #elif defined(SPECULAR_DISABLED) // none.. - float specular_brdf_NL = 0.0; #elif defined(SPECULAR_SCHLICK_GGX) // shlick+ggx as default @@ -1156,28 +1186,28 @@ 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 vec3 f0 = F0(metallic, specular, diffuse_color); float cLdotH5 = SchlickFresnel(cLdotH); vec3 F = mix(vec3(cLdotH5), vec3(1.0), f0); - vec3 specular_brdf_NL = cNdotL * D * F * G; + specular_brdf_NL = cNdotL * D * F * G; #endif @@ -1196,11 +1226,12 @@ 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 } |