@@ -23,26 +23,21 @@ define([
2323 /**
2424 * @private
2525 */
26- function processPbrMetallicRoughness ( gltf , options ) {
26+ function processPbrMaterials ( gltf , options ) {
2727 options = defaultValue ( options , { } ) ;
2828
29- var hasPbrMetallicRoughness = false ;
30- ForEach . material ( gltf , function ( material ) {
31- if ( isPbrMaterial ( material ) ) {
32- hasPbrMetallicRoughness = true ;
33- }
34- } ) ;
35-
36- if ( ! hasPbrMetallicRoughness ) {
37- return gltf ;
38- }
39-
4029 // No need to create new techniques if they already exist,
4130 // the shader should handle these values
4231 if ( hasExtension ( gltf , 'KHR_techniques_webgl' ) ) {
4332 return gltf ;
4433 }
4534
35+ // All materials in glTF are PBR by default,
36+ // so we should apply PBR unless no materials are found.
37+ if ( gltf . materials . length === 0 ) {
38+ return gltf ;
39+ }
40+
4641 if ( ! defined ( gltf . extensions ) ) {
4742 gltf . extensions = { } ;
4843 }
@@ -60,25 +55,24 @@ define([
6055 shaders : [ ] ,
6156 techniques : [ ]
6257 } ;
58+
6359 gltf . extensionsUsed . push ( 'KHR_techniques_webgl' ) ;
6460 gltf . extensionsRequired . push ( 'KHR_techniques_webgl' ) ;
6561
6662 var primitiveByMaterial = ModelUtility . splitIncompatibleMaterials ( gltf ) ;
6763
6864 ForEach . material ( gltf , function ( material , materialIndex ) {
69- if ( isPbrMaterial ( material ) ) {
70- var generatedMaterialValues = { } ;
71- var technique = generateTechnique ( gltf , material , materialIndex , generatedMaterialValues , primitiveByMaterial , options ) ;
72-
73- if ( ! defined ( material . extensions ) ) {
74- material . extensions = { } ;
75- }
65+ var generatedMaterialValues = { } ;
66+ var technique = generateTechnique ( gltf , material , materialIndex , generatedMaterialValues , primitiveByMaterial , options ) ;
7667
77- material . extensions . KHR_techniques_webgl = {
78- values : generatedMaterialValues ,
79- technique : technique
80- } ;
68+ if ( ! defined ( material . extensions ) ) {
69+ material . extensions = { } ;
8170 }
71+
72+ material . extensions . KHR_techniques_webgl = {
73+ values : generatedMaterialValues ,
74+ technique : technique
75+ } ;
8276 } ) ;
8377
8478 // If any primitives have semantics that aren't declared in the generated
@@ -88,15 +82,9 @@ define([
8882 return gltf ;
8983 }
9084
91- function isPbrMaterial ( material ) {
92- return defined ( material . pbrMetallicRoughness ) ||
93- defined ( material . normalTexture ) ||
94- defined ( material . occlusionTexture ) ||
95- defined ( material . emissiveTexture ) ||
96- defined ( material . emissiveFactor ) ||
97- defined ( material . alphaMode ) ||
98- defined ( material . alphaCutoff ) ||
99- defined ( material . doubleSided ) ;
85+ function isSpecularGlossinessMaterial ( material ) {
86+ return defined ( material . extensions ) &&
87+ defined ( material . extensions . KHR_materials_pbrSpecularGlossiness ) ;
10088 }
10189
10290 function generateTechnique ( gltf , material , materialIndex , generatedMaterialValues , primitiveByMaterial , options ) {
@@ -107,16 +95,30 @@ define([
10795 var shaders = techniquesWebgl . shaders ;
10896 var programs = techniquesWebgl . programs ;
10997
98+ var useSpecGloss = isSpecularGlossinessMaterial ( material ) ;
99+
110100 var uniformName ;
101+ var parameterName ;
111102 var pbrMetallicRoughness = material . pbrMetallicRoughness ;
112- if ( defined ( pbrMetallicRoughness ) ) {
113- for ( var parameterName in pbrMetallicRoughness ) {
103+ if ( defined ( pbrMetallicRoughness ) && ! useSpecGloss ) {
104+ for ( parameterName in pbrMetallicRoughness ) {
114105 if ( pbrMetallicRoughness . hasOwnProperty ( parameterName ) ) {
115106 uniformName = 'u_' + parameterName ;
116107 generatedMaterialValues [ uniformName ] = pbrMetallicRoughness [ parameterName ] ;
117108 }
118109 }
119110 }
111+
112+ if ( useSpecGloss ) {
113+ var pbrSpecularGlossiness = material . extensions . KHR_materials_pbrSpecularGlossiness ;
114+ for ( parameterName in pbrSpecularGlossiness ) {
115+ if ( pbrSpecularGlossiness . hasOwnProperty ( parameterName ) ) {
116+ uniformName = 'u_' + parameterName ;
117+ generatedMaterialValues [ uniformName ] = pbrSpecularGlossiness [ parameterName ] ;
118+ }
119+ }
120+ }
121+
120122 for ( var additional in material ) {
121123 if ( material . hasOwnProperty ( additional ) && ( ( additional . indexOf ( 'Texture' ) >= 0 ) || additional . indexOf ( 'Factor' ) >= 0 ) ) {
122124 uniformName = 'u_' + additional ;
@@ -538,8 +540,40 @@ define([
538540 fragmentShader += ' vec3 baseColor = baseColorWithAlpha.rgb;\n' ;
539541
540542 if ( hasNormals ) {
541- // Add metallic-roughness to fragment shader
542- if ( defined ( generatedMaterialValues . u_metallicRoughnessTexture ) ) {
543+ if ( useSpecGloss ) {
544+ if ( defined ( generatedMaterialValues . u_specularGlossinessTexture ) ) {
545+ fragmentShader += ' vec4 specularGlossiness = SRGBtoLINEAR4(texture2D(u_specularGlossinessTexture, ' + v_texcoord + '));\n' ;
546+ fragmentShader += ' vec3 specular = specularGlossiness.rgb;\n' ;
547+ fragmentShader += ' float glossiness = specularGlossiness.a;\n' ;
548+ if ( defined ( generatedMaterialValues . u_specularFactor ) ) {
549+ fragmentShader += ' specular *= u_specularFactor;\n' ;
550+ }
551+ if ( defined ( generatedMaterialValues . u_glossinessFactor ) ) {
552+ fragmentShader += ' glossiness *= u_glossinessFactor;\n' ;
553+ }
554+ } else {
555+ if ( defined ( generatedMaterialValues . u_specularFactor ) ) {
556+ fragmentShader += ' vec3 specular = clamp(u_specularFactor, vec3(0.0), vec3(1.0));\n' ;
557+ } else {
558+ fragmentShader += ' vec3 specular = vec3(1.0);\n' ;
559+ }
560+ if ( defined ( generatedMaterialValues . u_glossinessFactor ) ) {
561+ fragmentShader += ' float glossiness = clamp(u_glossinessFactor, 0.0, 1.0);\n' ;
562+ } else {
563+ fragmentShader += ' float glossiness = 1.0;\n' ;
564+ }
565+ }
566+ if ( defined ( generatedMaterialValues . u_diffuseTexture ) ) {
567+ fragmentShader += ' vec4 diffuse = SRGBtoLINEAR4(texture2D(u_diffuseTexture, ' + v_texcoord + '));\n' ;
568+ if ( defined ( generatedMaterialValues . u_diffuseFactor ) ) {
569+ fragmentShader += ' diffuse *= u_diffuseFactor;\n' ;
570+ }
571+ } else if ( defined ( generatedMaterialValues . u_diffuseFactor ) ) {
572+ fragmentShader += ' vec4 diffuse = clamp(u_diffuseFactor, vec4(0.0), vec4(1.0));\n' ;
573+ } else {
574+ fragmentShader += ' vec4 diffuse = vec4(1.0);\n' ;
575+ }
576+ } else if ( defined ( generatedMaterialValues . u_metallicRoughnessTexture ) ) {
543577 fragmentShader += ' vec3 metallicRoughness = texture2D(u_metallicRoughnessTexture, ' + v_texcoord + ').rgb;\n' ;
544578 fragmentShader += ' float metalness = clamp(metallicRoughness.b, 0.0, 1.0);\n' ;
545579 fragmentShader += ' float roughness = clamp(metallicRoughness.g, 0.04, 1.0);\n' ;
@@ -561,6 +595,7 @@ define([
561595 fragmentShader += ' float roughness = 1.0;\n' ;
562596 }
563597 }
598+
564599 fragmentShader += ' vec3 v = -normalize(v_positionEC);\n' ;
565600
566601 // Generate fragment shader's lighting block
@@ -583,11 +618,19 @@ define([
583618 fragmentShader += ' float NdotH = clamp(dot(n, h), 0.0, 1.0);\n' ;
584619 fragmentShader += ' float LdotH = clamp(dot(l, h), 0.0, 1.0);\n' ;
585620 fragmentShader += ' float VdotH = clamp(dot(v, h), 0.0, 1.0);\n' ;
586-
587621 fragmentShader += ' vec3 f0 = vec3(0.04);\n' ;
622+ // Whether the material uses metallic-roughness or specular-glossiness changes how the BRDF inputs are computed.
623+ // It does not change the implementation of the BRDF itself.
624+ if ( useSpecGloss ) {
625+ fragmentShader += ' float roughness = 1.0 - glossiness;\n' ;
626+ fragmentShader += ' vec3 diffuseColor = diffuse.rgb * (1.0 - max(max(specular.r, specular.g), specular.b));\n' ;
627+ fragmentShader += ' vec3 specularColor = specular;\n' ;
628+ } else {
629+ fragmentShader += ' vec3 diffuseColor = baseColor * (1.0 - metalness) * (1.0 - f0);\n' ;
630+ fragmentShader += ' vec3 specularColor = mix(f0, baseColor, metalness);\n' ;
631+ }
632+
588633 fragmentShader += ' float alpha = roughness * roughness;\n' ;
589- fragmentShader += ' vec3 diffuseColor = baseColor * (1.0 - metalness) * (1.0 - f0);\n' ;
590- fragmentShader += ' vec3 specularColor = mix(f0, baseColor, metalness);\n' ;
591634 fragmentShader += ' float reflectance = max(max(specularColor.r, specularColor.g), specularColor.b);\n' ;
592635 fragmentShader += ' vec3 r90 = vec3(clamp(reflectance * 25.0, 0.0, 1.0));\n' ;
593636 fragmentShader += ' vec3 r0 = specularColor.rgb;\n' ;
@@ -725,8 +768,19 @@ define([
725768 return WebGLConstants . SAMPLER_2D ;
726769 case 'u_emissiveFactor' :
727770 return WebGLConstants . FLOAT_VEC3 ;
771+ // Specular Glossiness Types
772+ case 'u_diffuseFactor' :
773+ return WebGLConstants . FLOAT_VEC4 ;
774+ case 'u_specularFactor' :
775+ return WebGLConstants . FLOAT_VEC3 ;
776+ case 'u_glossinessFactor' :
777+ return WebGLConstants . FLOAT ;
778+ case 'u_diffuseTexture' :
779+ return WebGLConstants . SAMPLER_2D ;
780+ case 'u_specularGlossinessTexture' :
781+ return WebGLConstants . SAMPLER_2D ;
728782 }
729783 }
730784
731- return processPbrMetallicRoughness ;
785+ return processPbrMaterials ;
732786} ) ;
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