Indexed multi-material batching for GLTF PBR and legacy materials

indra/llrender/llglslshader.cpp

@@ -54,6 +54,8 @@ using std::string;
 GLuint LLGLSLShader::sCurBoundShader = 0;
 LLGLSLShader* LLGLSLShader::sCurBoundShaderPtr = NULL;
 S32 LLGLSLShader::sIndexedTextureChannels = 0;
+S32 LLGLSLShader::sIndexedGLTFChannels = 0;
+bool LLGLSLShader::sIndexedLegacyMaterials = false;
 U32 LLGLSLShader::sMaxGLTFMaterials = 0;
 U32 LLGLSLShader::sMaxGLTFNodes = 0;
 bool LLGLSLShader::sProfileEnabled = false;

indra/llrender/llglslshader.h

@@ -171,6 +171,17 @@ class LLGLSLShader
     static LLGLSLShader* sCurBoundShaderPtr;
     static S32 sIndexedTextureChannels;
 
+    // Number of GLTF PBR materials that can be batched into one indexed draw call.
+    // Each material consumes four texture units (base color, normal, ORM, emissive),
+    // so this is roughly (available fragment texture units) / 4. See
+    // PASS_GLTF_PBR_INDEXED and LLVolumeGeometryManager::genDrawInfo.
+    static S32 sIndexedGLTFChannels;
+
+    // True once the indexed legacy (Blinn-Phong) material programs have loaded.
+    // Gates indexed POOL_MATERIALS batching (shares sIndexedGLTFChannels for the
+    // per-slot stride); independent so a material-shader failure doesn't disable PBR.
+    static bool sIndexedLegacyMaterials;
+
     static U32 sMaxGLTFMaterials;
     static U32 sMaxGLTFNodes;
 

indra/newview/app_settings/settings_alchemy.xml

@@ -1235,6 +1235,17 @@
             <key>Value</key>
             <integer>1</integer>
         </map>
+        <key>RenderGLTFPBRBatching</key>
+        <map>
+            <key>Comment</key>
+            <string>Batch multiple materials into a single indexed draw call across the supported GLTF PBR and legacy material passes (opaque, alpha-mask, rigged, shadow, glow). 0 = one draw call per material (legacy), 1 = indexed multi-material batching. Reduces draw calls in material-heavy scenes.</string>
+            <key>Persist</key>
+            <integer>1</integer>
+            <key>Type</key>
+            <string>Boolean</string>
+            <key>Value</key>
+            <integer>1</integer>
+        </map>
         <key>RenderBloomThreshold</key>
         <map>
             <key>Comment</key>

indra/newview/app_settings/shaders/class1/deferred/emissiveIndexedF.glsl

@@ -0,0 +1,94 @@
+/**
+ * @file emissiveIndexedF.glsl
+ *
+ * $LicenseInfo:firstyear=2007&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2007, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+/*[EXTRA_CODE_HERE]*/
+
+// Indexed (multi-material) variant of emissiveF.glsl (legacy glow). Only alpha is
+// written. vary_material_index selects this primitive's diffuse map (bound to unit
+// s); its alpha modulates the per-vertex glow factor. If-chains (not switch) are
+// used for driver portability.
+
+out vec4 frag_color;
+
+in vec4 vertex_color;
+in vec2 vary_texcoord0;
+flat in int vary_material_index;
+
+uniform sampler2D diffuse0;
+#if GLTF_INDEXED_CHANNELS > 1
+uniform sampler2D diffuse1;
+#endif
+#if GLTF_INDEXED_CHANNELS > 2
+uniform sampler2D diffuse2;
+#endif
+#if GLTF_INDEXED_CHANNELS > 3
+uniform sampler2D diffuse3;
+#endif
+#if GLTF_INDEXED_CHANNELS > 4
+uniform sampler2D diffuse4;
+#endif
+#if GLTF_INDEXED_CHANNELS > 5
+uniform sampler2D diffuse5;
+#endif
+#if GLTF_INDEXED_CHANNELS > 6
+uniform sampler2D diffuse6;
+#endif
+#if GLTF_INDEXED_CHANNELS > 7
+uniform sampler2D diffuse7;
+#endif
+
+vec4 sample_diffuse(vec2 uv)
+{
+    if (vary_material_index == 0) return texture(diffuse0, uv);
+#if GLTF_INDEXED_CHANNELS > 1
+    if (vary_material_index == 1) return texture(diffuse1, uv);
+#endif
+#if GLTF_INDEXED_CHANNELS > 2
+    if (vary_material_index == 2) return texture(diffuse2, uv);
+#endif
+#if GLTF_INDEXED_CHANNELS > 3
+    if (vary_material_index == 3) return texture(diffuse3, uv);
+#endif
+#if GLTF_INDEXED_CHANNELS > 4
+    if (vary_material_index == 4) return texture(diffuse4, uv);
+#endif
+#if GLTF_INDEXED_CHANNELS > 5
+    if (vary_material_index == 5) return texture(diffuse5, uv);
+#endif
+#if GLTF_INDEXED_CHANNELS > 6
+    if (vary_material_index == 6) return texture(diffuse6, uv);
+#endif
+#if GLTF_INDEXED_CHANNELS > 7
+    if (vary_material_index == 7) return texture(diffuse7, uv);
+#endif
+    return vec4(1, 0, 1, 1);
+}
+
+void main()
+{
+    // NOTE: when this shader is used, only alpha is being written to
+    float a = sample_diffuse(vary_texcoord0.xy).a * vertex_color.a;
+    frag_color = max(vec4(0, 0, 0, a), vec4(0));
+}

indra/newview/app_settings/shaders/class1/deferred/emissiveIndexedV.glsl

@@ -0,0 +1,63 @@
+/**
+ * @file emissiveIndexedV.glsl
+ *
+ * $LicenseInfo:firstyear=2007&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2007, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+// Indexed (multi-material) variant of emissiveV.glsl (legacy glow). Forwards the
+// per-vertex material slot to the fragment shader so each slot's diffuse alpha can
+// be sampled. The diffuse texture transform is baked into texcoord0 at buffer build
+// (indexed faces exclude texture animation), so texture_matrix0 is not applied.
+// HAS_SKIN adds rigged matrix-palette skinning.
+
+#ifdef HAS_SKIN
+uniform mat4 modelview_matrix;
+uniform mat4 projection_matrix;
+mat4 getObjectSkinnedTransform();
+#else
+uniform mat4 modelview_projection_matrix;
+#endif
+
+in vec3 position;
+in vec4 emissive;
+in vec2 texcoord0;
+in int texture_index;
+
+flat out int vary_material_index;
+out vec4 vertex_color;
+out vec2 vary_texcoord0;
+
+void main()
+{
+#ifdef HAS_SKIN
+    mat4 mat = getObjectSkinnedTransform();
+    mat = modelview_matrix * mat;
+    vec3 pos = (mat*vec4(position.xyz,1.0)).xyz;
+    gl_Position = projection_matrix*vec4(pos,1.0);
+#else
+    gl_Position = modelview_projection_matrix * vec4(position.xyz, 1.0);
+#endif
+
+    vary_material_index = texture_index;
+    vary_texcoord0 = texcoord0;
+    vertex_color = emissive;
+}