From 8ef657e5b2066ca9544f39b4c2f228a740718cb5 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Fri, 28 Feb 2014 17:05:08 -0800
Subject: [PATCH] Render avatar collision shapes in the right spot

---
 interface/src/renderer/Model.cpp | 11 ++++++++---
 interface/src/renderer/Model.h   |  8 ++++----
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/interface/src/renderer/Model.cpp b/interface/src/renderer/Model.cpp
index 47a6013b5f..48cfde8be6 100644
--- a/interface/src/renderer/Model.cpp
+++ b/interface/src/renderer/Model.cpp
@@ -137,9 +137,10 @@ void Model::createCollisionShapes() {
     const FBXGeometry& geometry = _geometry->getFBXGeometry();
     float uniformScale = extractUniformScale(_scale);
     for (int i = 0; i < _jointStates.size(); i++) {
-        glm::vec3 position = extractTranslation(_jointStates[i].transform);
         const FBXJoint& joint = geometry.joints[i];
-        // for now make everything a sphere at joint end
+        glm::vec3 meshCenter = _jointStates[i].combinedRotation * joint.averageVertex;
+        glm::vec3 position = _rotation * (extractTranslation(_jointStates[i].transform) + uniformScale * meshCenter) + _translation;
+
         float radius = uniformScale * joint.boneRadius;
         SphereShape* shape = new SphereShape(radius, position);
         _shapes.push_back(shape);
@@ -147,10 +148,14 @@ void Model::createCollisionShapes() {
 }
 
 void Model::updateShapePositions() {
+    float uniformScale = extractUniformScale(_scale);
+    const FBXGeometry& geometry = _geometry->getFBXGeometry();
     if (_shapesAreDirty && _shapes.size() == _jointStates.size()) {
         for (int i = 0; i < _jointStates.size(); i++) {
+            const FBXJoint& joint = geometry.joints[i];
             // shape positions are stored in world-frame
-            _shapes[i]->setPosition(_rotation * extractTranslation(_jointStates[i].transform) + _translation);
+            glm::vec3 meshCenter = _jointStates[i].combinedRotation * joint.averageVertex;
+            _shapes[i]->setPosition(_rotation * (extractTranslation(_jointStates[i].transform) + uniformScale * meshCenter) + _translation);
             _shapes[i]->setRotation(_jointStates[i].combinedRotation);
         }
         _shapesAreDirty = false;
diff --git a/interface/src/renderer/Model.h b/interface/src/renderer/Model.h
index eff2bb0594..12691dbf03 100644
--- a/interface/src/renderer/Model.h
+++ b/interface/src/renderer/Model.h
@@ -182,10 +182,10 @@ protected:
     
     class JointState {
     public:
-        glm::vec3 translation;
-        glm::quat rotation;
-        glm::mat4 transform;
-        glm::quat combinedRotation;
+        glm::vec3 translation;  // translation relative to parent
+        glm::quat rotation;     // rotation relative to parent
+        glm::mat4 transform;    // rotation to world frame + translation in model frame
+        glm::quat combinedRotation; // rotation to world frame
     };
     
     bool _shapesAreDirty;