#1718 Add GLTF support for multiple texcoords (#1720)

* Fix for GLTF MeshPrimitiveModes test

2 files changed, 89 insertions, 23 deletions

diff --git a/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessF.glsl b/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessF.glsl
index 99bfcf70fa..789c00259b 100644
--- a/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessF.glsl
+++ b/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessF.glsl
@@ -37,8 +37,8 @@ uniform sampler2D emissiveMap;
 uniform vec3 emissiveColor;
 in vec3 vary_position;
 in vec4 vertex_color;
-in vec2 base_color_texcoord;
-in vec2 emissive_texcoord;
+in vec2 base_color_uv;
+in vec2 emissive_uv;
 uniform float minimum_alpha;
 
 void mirrorClip(vec3 pos);
@@ -59,9 +59,9 @@ uniform float roughnessFactor;
 in vec3 vary_normal;
 in vec3 vary_tangent;
 flat in float vary_sign;
-in vec2 normal_texcoord;
-in vec2 metallic_roughness_texcoord;
-in vec2 occlusion_texcoord;
+in vec2 normal_uv;
+in vec2 metallic_roughness_uv;
+in vec2 occlusion_uv;
 #endif
 // ==================================
 
@@ -165,7 +165,7 @@ void main()
     vec3 pos = vary_position;
     mirrorClip(pos);
 
-    vec4 basecolor = texture(diffuseMap, base_color_texcoord.xy).rgba;
+    vec4 basecolor = texture(diffuseMap, base_color_uv.xy).rgba;
     basecolor.rgb = srgb_to_linear(basecolor.rgb);
     basecolor *= vertex_color;
 
@@ -175,7 +175,7 @@ void main()
     }
 
     vec3 emissive = emissiveColor;
-    emissive *= srgb_to_linear(texture(emissiveMap, emissive_texcoord.xy).rgb);
+    emissive *= srgb_to_linear(texture(emissiveMap, emissive_uv.xy).rgb);
 // ==================================
 
 // ==================================
@@ -185,7 +185,7 @@ void main()
 // ==================================
 #ifndef UNLIT
     // from mikktspace.com
-    vec3 vNt = texture(normalMap, normal_texcoord.xy).xyz*2.0-1.0;
+    vec3 vNt = texture(normalMap, normal_uv.xy).xyz*2.0-1.0;
     float sign = vary_sign;
     vec3 vN = vary_normal;
     vec3 vT = vary_tangent.xyz;
@@ -199,8 +199,8 @@ void main()
     //   occlusion 1.0
     //   roughness 0.0
     //   metal     0.0
-    vec3 orm = texture(metallicRoughnessMap, metallic_roughness_texcoord.xy).rgb;
-    orm.r = texture(occlusionMap, occlusion_texcoord.xy).r;
+    vec3 orm = texture(metallicRoughnessMap, metallic_roughness_uv.xy).rgb;
+    orm.r = texture(occlusionMap, occlusion_uv.xy).r;
     orm.g *= roughnessFactor;
     orm.b *= metallicFactor;
 #endif
diff --git a/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessV.glsl b/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessV.glsl
index bc9a47d41e..aac3dc917f 100644
--- a/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessV.glsl
+++ b/indra/newview/app_settings/shaders/class1/gltf/pbrmetallicroughnessV.glsl
@@ -33,7 +33,6 @@ uniform mat4 projection_matrix;
 uniform mat3 normal_matrix;
 uniform mat4 modelview_projection_matrix;
 #endif
-uniform mat4 texture_matrix0;
 
 uniform vec4[2] texture_base_color_transform;
 uniform vec4[2] texture_normal_transform;
@@ -44,21 +43,31 @@ uniform vec4[2] texture_occlusion_transform;
 in vec3 position;
 in vec4 diffuse_color;
 in vec2 texcoord0;
-out vec2 base_color_texcoord;
-out vec2 emissive_texcoord;
+out vec2 base_color_uv;
+out vec2 emissive_uv;
 out vec4 vertex_color;
 out vec3 vary_position;
 
 #ifndef UNLIT
 in vec3 normal;
 in vec4 tangent;
-out vec2 normal_texcoord;
-out vec2 metallic_roughness_texcoord;
-out vec2 occlusion_texcoord;
+out vec2 normal_uv;
+out vec2 metallic_roughness_uv;
+out vec2 occlusion_uv;
 out vec3 vary_tangent;
 flat out float vary_sign;
 out vec3 vary_normal;
-vec3 tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform, mat4 sl_animation_transform);
+#endif
+
+#ifdef MULTI_UV
+in vec2 texcoord1;
+uniform int base_color_texcoord;
+uniform int emissive_texcoord;
+#ifndef UNLIT
+uniform int normal_texcoord;
+uniform int metallic_roughness_texcoord;
+uniform int occlusion_texcoord;
+#endif
 #endif
 
 vec2 gltf_texture_transform(vec2 texcoord, vec4[2] p)
@@ -86,6 +95,36 @@ vec2 gltf_texture_transform(vec2 texcoord, vec4[2] p)
     return uvTransformed;
 }
 
+#ifndef UNLIT
+vec3 gltf_tangent_space_transform(vec4 vertex_tangent, vec3 vertex_normal, vec4[2] khr_gltf_transform)
+{ //derived from tangent_space_transform in textureUtilV.glsl
+    vec2 weights = vec2(0, 1);
+
+    // Convert to left-handed coordinate system
+    weights.y = -weights.y;
+
+    // Apply KHR_texture_transform (rotation only)
+    float khr_rotation = khr_gltf_transform[0].z;
+    mat2 khr_rotation_mat = mat2(
+        cos(khr_rotation),-sin(khr_rotation),
+        sin(khr_rotation), cos(khr_rotation)
+    );
+    weights = khr_rotation_mat * weights;
+
+    // Convert back to right-handed coordinate system
+    weights.y = -weights.y;
+
+    // Similar to the MikkTSpace-compatible method of extracting the binormal
+    // from the normal and tangent, as seen in the fragment shader
+    vec3 vertex_binormal = vertex_tangent.w * cross(vertex_normal, vertex_tangent.xyz);
+
+    return (weights.x * vertex_binormal.xyz) + (weights.y * vertex_tangent.xyz);
+
+    return vertex_tangent.xyz;
+}
+#endif
+
+
 
 #ifdef ALPHA_BLEND
 out vec3 vary_fragcoord;
@@ -161,13 +200,40 @@ void main()
     gl_Position = vert;
 #endif
 
-    base_color_texcoord = gltf_texture_transform(texcoord0, texture_base_color_transform);
-    emissive_texcoord = gltf_texture_transform(texcoord0, texture_emissive_transform);
+    vec2 bcuv;
+    vec2 emuv;
+
+#ifdef MULTI_UV
+    vec2 uv[2];
+    uv[0] = texcoord0;
+    uv[1] = texcoord1;
+
+    bcuv = uv[base_color_texcoord];
+    emuv = uv[emissive_texcoord];
+#else
+    bcuv = texcoord0;
+    emuv = texcoord0;
+#endif
+
+    base_color_uv = gltf_texture_transform(bcuv, texture_base_color_transform);
+    emissive_uv = gltf_texture_transform(emuv, texture_emissive_transform);
 
 #ifndef UNLIT
-    normal_texcoord = gltf_texture_transform(texcoord0, texture_normal_transform);
-    metallic_roughness_texcoord = gltf_texture_transform(texcoord0, texture_metallic_roughness_transform);
-    occlusion_texcoord = gltf_texture_transform(texcoord0, texture_occlusion_transform);
+    vec2 normuv;
+    vec2 rmuv;
+    vec2 ouv;
+#ifdef MULTI_UV
+    normuv = uv[normal_texcoord];
+    rmuv = uv[metallic_roughness_texcoord];
+    ouv = uv[occlusion_texcoord];
+#else
+    normuv = texcoord0;
+    rmuv = texcoord0;
+    ouv = texcoord0;
+#endif
+    normal_uv = gltf_texture_transform(normuv, texture_normal_transform);
+    metallic_roughness_uv = gltf_texture_transform(rmuv, texture_metallic_roughness_transform);
+    occlusion_uv = gltf_texture_transform(ouv, texture_occlusion_transform);
 #endif
 
 #ifndef UNLIT
@@ -180,7 +246,7 @@ void main()
 #endif
 
     n = normalize(n);
-    vary_tangent = normalize(tangent_space_transform(vec4(t, tangent.w), n, texture_normal_transform, texture_matrix0));
+    vary_tangent = normalize(gltf_tangent_space_transform(vec4(t, tangent.w), n, texture_normal_transform));
     vary_sign = tangent.w;
     vary_normal = n;
 #endif