EXT_mesh_gpu_instancing

extensions/2.0/Khronos/KHR_instancing/extensions/2.0/Khronos/KHR_instancing/README.md

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+# KHR\_instancing
+
+## Khronos 3D Formats Working Group
+
+* John Cooke
+* TODO
+
+## Acknowledgments
+
+* TODO
+
+## Status
+
+Experimental
+
+## Dependencies
+
+Written against the glTF 2.0 spec.
+
+## Overview
+
+This extension is specfically designed to enable GPU instancing which renders many copies of a single mesh at once using a small number of draw calls.  It's useful for things 
+like trees, grass, road signs, etc.  The TRANSFORM attribute allows the mesh to be displayed at many different locations with different rotations and scales.  The ID attribute 
+can be used to alter other parameters based on the run-time inplementation.
+
+## Extending Nodes with per instance attributes
+
+Instancing is defined by adding the `KHR_instancing` extension to any glTF node that has a mesh.  Instancing only applies to mesh nodes, there is no defined behavior for a node 
+with this extension that doesn't also have a mesh.  Applying to nodes rather than meshes allows the same mesh to be used by several nodes, instanced or otherwise.  The attributes 
+section contains accessor ids for the new TRANSFORM and ID attribute buffers.  For example, the following defines some instancing attributes to a node with mesh.  
+
+```json
+{
+    "nodes": [
+        {
+            "mesh": 0,
+            "name": "teapot",
+            "extensions": {
+                "KHR_instancing": {
+                    "attributes": {
+                        "TRANSFORM": 0,
+                        "ID": 1
+                    },
+                }
+            }
+        }
+    ]
+}
+```
+
+## Appendix
+
+TODO
+
+## Reference
+
+TODO
+
+### Theory, Documentation and Implementations
+
+TODO

extensions/2.0/Khronos/KHR_instancing/extensions/2.0/Khronos/KHR_instancing/schema/glTF.KHR_instancing.schema.json

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+{
+    "$schema": "http://json-schema.org/draft-04/schema",
+    "title": "KHR_instancing glTF extension",
+    "type": "object",
+    "description": "glTF extension defines instance attributes for a node with a mesh.",
+    "allOf": [ { "$ref": "glTFProperty.schema.json" } ],
+    "properties": {
+        "attributes": {
+            "type": "object",
+            "description": "A dictionary object, where each key corresponds to mesh attribute semantic and each value is the index of the accessor containing attribute's data (current valid attribs are TRANSFORM, ID).",
+            "minProperties": 1,
+            "additionalProperties": {
+                "$ref": "glTFid.schema.json"
+            }
+        },
+        "extensions": { },
+        "extras": { }
+    }
+}