precision mediump float;
#endif
-#ifdef THREE_TEX
#ifdef GLTF_CHANNELS
#define METALLIC b
#define ROUGHNESS g
#define METALLIC r
#define ROUGHNESS a
#endif //GLTF_CHANNELS
-#endif //THREE_TEX
-uniform lowp vec4 uColorFactor;
+uniform lowp vec4 uColor; // Color from SceneGraph
+uniform lowp vec4 uColorFactor; // Color from material
uniform lowp float uMetallicFactor;
uniform lowp float uRoughnessFactor;
+uniform lowp float uDielectricSpecular;
#ifdef THREE_TEX
#ifdef BASECOLOR_TEX
uniform vec3 uEmissiveFactor;
#endif
+uniform float uSpecularFactor;
+uniform vec3 uSpecularColorFactor;
+#ifdef MATERIAL_SPECULAR_TEXTURE
+uniform sampler2D sSpecular;
+#endif
+#ifdef MATERIAL_SPECULAR_COLOR_TEXTURE
+uniform sampler2D sSpecularColor;
+#endif
+
//// For IBL
uniform sampler2D sbrdfLUT;
uniform samplerCube sDiffuseEnvSampler;
uniform lowp float uAlphaThreshold;
// TODO: Multiple texture coordinate will be supported.
-in lowp vec2 vUV;
+in mediump vec2 vUV;
in lowp mat3 vTBN;
+#ifdef COLOR_ATTRIBUTE
in lowp vec4 vColor;
+#endif
in highp vec3 vPositionToCamera;
out vec4 FragColor;
-struct PBRInfo
-{
- mediump float NdotL; // cos angle between normal and light direction
- mediump float NdotV; // cos angle between normal and view direction
- mediump float NdotH; // cos angle between normal and half vector
- mediump float VdotH; // cos angle between view direction and half vector
- mediump vec3 reflectance0; // full reflectance color (normal incidence angle)
- mediump vec3 reflectance90; // reflectance color at grazing angle
- lowp float alphaRoughness; // roughness mapped to a more linear change in the roughness (proposed by [2])
-};
-
-const float M_PI = 3.141592653589793;
const float c_MinRoughness = 0.04;
-vec3 specularReflection(PBRInfo pbrInputs)
-{
- return pbrInputs.reflectance0 + (pbrInputs.reflectance90 - pbrInputs.reflectance0) * pow(clamp(1.0 - pbrInputs.VdotH, 0.0, 1.0), 5.0);
-}
-
-float geometricOcclusion(PBRInfo pbrInputs)
-{
- mediump float NdotL = pbrInputs.NdotL;
- mediump float NdotV = pbrInputs.NdotV;
- lowp float r = pbrInputs.alphaRoughness;
-
- lowp float attenuationL = 2.0 * NdotL / (NdotL + sqrt(r * r + (1.0 - r * r) * (NdotL * NdotL)));
- lowp float attenuationV = 2.0 * NdotV / (NdotV + sqrt(r * r + (1.0 - r * r) * (NdotV * NdotV)));
- return attenuationL * attenuationV;
-}
-
-float microfacetDistribution(PBRInfo pbrInputs)
-{
- mediump float roughnessSq = pbrInputs.alphaRoughness * pbrInputs.alphaRoughness;
- lowp float f = (pbrInputs.NdotH * roughnessSq - pbrInputs.NdotH) * pbrInputs.NdotH + 1.0;
- return roughnessSq / (M_PI * f * f);
-}
-
vec3 linear(vec3 color)
{
return pow(color, vec3(2.2));
lowp vec4 baseColor = texture(sAlbedoAlpha, vUV);
baseColor = vec4(linear(baseColor.rgb), baseColor.w) * uColorFactor;
#else // BASECOLOR_TEX
+#ifdef COLOR_ATTRIBUTE
lowp vec4 baseColor = vColor * uColorFactor;
+#else // COLOR_ATTRIBUTE
+ lowp vec4 baseColor = uColorFactor;
+#endif // COLOR_ATTRIBUTE
#endif // BASECOLOR_TEX
#ifdef METALLIC_ROUGHNESS_TEX
#endif // NORMAL_TEX
#else // THREE_TEX
vec4 albedoMetal = texture(sAlbedoMetal, vUV);
+#ifdef COLOR_ATTRIBUTE
lowp vec4 baseColor = vec4(linear(albedoMetal.rgb), 1.0) * vColor * uColorFactor;
+#else // COLOR_ATTRIBUTE
+ lowp vec4 baseColor = vec4(linear(albedoMetal.rgb), 1.0) * uColorFactor;
+#endif // COLOR_ATTRIBUTE
metallic = albedoMetal.METALLIC * metallic;
#endif // THREE_TEX
// The value of uOpaque and uMask can be 0.0 or 1.0.
+ // If uMask is 1.0, a Pixel that has bigger alpha than uAlphaThreashold becomes fully opaque,
+ // and, a pixel that has smaller alpha than uAlphaThreashold becomes fully transparent.
// If uOpaque is 1.0, alpha value of final color is 1.0;
- // If uOpaque is 0.0 and uMask is 1.0, alpha value of final color is 0.0 when input alpha is lower than uAlphaThreshold or
- // 1.0 when input alpha is larger than uAlphaThreshold.
// https://www.khronos.org/registry/glTF/specs/2.0/glTF-2.0.html#_material_alphamode
+ if(uMask > 0.5 && baseColor.a < uAlphaThreshold)
+ {
+ discard;
+ }
baseColor.a = mix(baseColor.a, 1.0, uOpaque);
- baseColor.a = min(mix(baseColor.a, floor(baseColor.a - uAlphaThreshold + 1.0), uMask), 1.0);
metallic = clamp(metallic, 0.0, 1.0);
// Roughness is authored as perceptual roughness; as is convention,
// convert to material roughness by squaring the perceptual roughness [2].
perceptualRoughness = clamp(perceptualRoughness, c_MinRoughness, 1.0);
- lowp float alphaRoughness = perceptualRoughness * perceptualRoughness;
-
- lowp vec3 f0 = vec3(0.04);
- lowp vec3 diffuseColor = baseColor.rgb * (vec3(1.0) - f0);
- diffuseColor *= (1.0 - metallic);
- lowp vec3 specularColor = mix(f0, baseColor.rgb, metallic);
- // Compute reflectance.
- lowp float reflectance = max(max(specularColor.r, specularColor.g), specularColor.b);
+ // Material ior
+ lowp vec3 f0 = vec3(uDielectricSpecular);
- // For typical incident reflectance range (between 4% to 100%) set the grazing reflectance to 100% for typical fresnel effect.
- // For very low reflectance range on highly diffuse objects (below 4%), incrementally reduce grazing reflecance to 0%.
- lowp float reflectance90 = clamp(reflectance * 25.0, 0.0, 1.0);
- lowp vec3 specularEnvironmentR0 = specularColor.rgb;
- lowp vec3 specularEnvironmentR90 = vec3(1.0, 1.0, 1.0) * reflectance90;
+ // Material Specular
+ float specularWeight = 1.0;
+ vec4 materialSpecularTexture = vec4(1.0);
+#ifdef MATERIAL_SPECULAR_TEXTURE
+ materialSpecularTexture.a = texture(sSpecular, vUV).a;
+#endif
+#ifdef MATERIAL_SPECULAR_COLOR_TEXTURE
+ materialSpecularTexture.rgb = texture(sSpecularColor, vUV).rgb;
+#endif
+ specularWeight = uSpecularFactor * materialSpecularTexture.a;
+ f0 = min(f0 * uSpecularColorFactor * materialSpecularTexture.rgb, vec3(1.0));
+ f0 = mix(f0, baseColor.rgb, metallic);
mediump vec3 v = normalize(vPositionToCamera); // Vector from surface point to camera
mediump float NdotV = clamp(abs(dot(n, v)), 0.001, 1.0);
mediump vec3 reflection = -normalize(reflect(v, n));
+ lowp vec3 brdf = linear(texture(sbrdfLUT, vec2(NdotV, 1.0 - perceptualRoughness)).rgb);
+ vec3 Fr = max(vec3(1.0 - perceptualRoughness), f0) - f0;
+ vec3 k_S = f0 + Fr * pow(1.0 - NdotV, 5.0);
+ vec3 FssEss = specularWeight * (k_S * brdf.x + brdf.y);
- lowp vec3 color = vec3(0.0);
- lowp vec3 diffuseLight = linear(texture(sDiffuseEnvSampler, n * uYDirection).rgb);
+ // Specular Light
lowp vec3 specularLight = linear(texture(sSpecularEnvSampler, reflection * uYDirection).rgb);
- // retrieve a scale and bias to F0. See [1], Figure 3
- lowp vec3 brdf = linear(texture(sbrdfLUT, vec2(NdotV, 1.0 - perceptualRoughness)).rgb);
+ lowp vec3 specular = specularLight * FssEss;
+
+ // Diffuse Light
+ lowp vec3 diffuseColor = mix(baseColor.rgb, vec3(0), metallic);
+ lowp vec3 irradiance = linear(texture(sDiffuseEnvSampler, n * uYDirection).rgb);
+ float Ems = (1.0 - (brdf.x + brdf.y));
+ vec3 F_avg = specularWeight * (f0 + (1.0 - f0) / 21.0);
+ vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
+ vec3 k_D = diffuseColor * (1.0 - FssEss + FmsEms);
+ lowp vec3 diffuse = (FmsEms + k_D) * irradiance;
- lowp vec3 diffuse = diffuseLight * diffuseColor;
- lowp vec3 specular = specularLight * (specularColor * brdf.x + brdf.y);
- color += (diffuse + specular) * uIblIntensity;
+ lowp vec3 color = (diffuse + specular) * uIblIntensity;
#ifdef OCCLUSION
lowp float ao = texture(sOcclusion, vUV).r;
color += emissive;
#endif // EMISSIVE
- FragColor = vec4(pow(color, vec3(1.0 / 2.2)), baseColor.a);
+ FragColor = vec4(pow(color, vec3(1.0 / 2.2)), baseColor.a) * uColor;
}