From cb8e68f300cfca0e777f3096347c65fe2f3b8c7b Mon Sep 17 00:00:00 2001
From: Jeffrey Ventrella <jeffreyventrella@gmail.com>
Date: Fri, 3 May 2013 16:11:35 -0700
Subject: [PATCH] fixed a physics bug in avatar body spring (forgot to use
 deltaTime) - and adjusted various physics constants accordingly.

---
 interface/src/Avatar.cpp | 26 ++++++++++++++++----------
 interface/src/Util.cpp   |  8 +++++---
 interface/src/main.cpp   |  2 +-
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/interface/src/Avatar.cpp b/interface/src/Avatar.cpp
index a80fea7dc9..24dae3c35d 100644
--- a/interface/src/Avatar.cpp
+++ b/interface/src/Avatar.cpp
@@ -32,9 +32,14 @@ const float BODY_ROLL_WHILE_TURNING       = 0.1;
 const float LIN_VEL_DECAY                 = 5.0;
 const float MY_HAND_HOLDING_PULL          = 0.2;
 const float YOUR_HAND_HOLDING_PULL        = 1.0;
-const float BODY_SPRING_FORCE             = 6.0f;
+
+//const float BODY_SPRING_DEFAULT_TIGHTNESS = 20.0f;
+//const float BODY_SPRING_FORCE             = 6.0f;
+
+const float BODY_SPRING_DEFAULT_TIGHTNESS = 1500.0f;
+const float BODY_SPRING_FORCE             = 300.0f;
+
 const float BODY_SPRING_DECAY             = 16.0f;
-const float BODY_SPRING_DEFAULT_TIGHTNESS = 20.0f;
 const float COLLISION_RADIUS_SCALAR       = 1.8;
 const float COLLISION_BALL_FORCE          = 1.0;
 const float COLLISION_BODY_FORCE          = 6.0;
@@ -336,10 +341,6 @@ void Avatar::simulate(float deltaTime) {
     //update the movement of the hand and process handshaking with other avatars... 
     updateHandMovementAndTouching(deltaTime);
         
-    // test for avatar collision response with the big sphere
-    if (usingBigSphereCollisionTest) {
-        updateCollisionWithSphere( _TEST_bigSpherePosition, _TEST_bigSphereRadius, deltaTime );
-    }
     
     // apply gravity and collision wiht the ground/floor
     if ( AVATAR_GRAVITY ) {
@@ -354,6 +355,11 @@ void Avatar::simulate(float deltaTime) {
 	// update body springs
     updateBodySprings( deltaTime );
     
+    // test for avatar collision response with the big sphere
+    if (usingBigSphereCollisionTest) {
+        updateCollisionWithSphere( _TEST_bigSpherePosition, _TEST_bigSphereRadius, deltaTime );
+    }
+    
     // driving the avatar around should only apply if this is my avatar (as opposed to an avatar being driven remotely)
     if ( _isMine ) {
         
@@ -670,9 +676,9 @@ void Avatar::updateCollisionWithSphere( glm::vec3 position, float radius, float
                     float penetration = 1.0 - (distanceToBigSphereCenter / combinedRadius);
                     glm::vec3 collisionForce = vectorFromJointToBigSphereCenter * penetration;
                     
-                    _joint[b].springyVelocity += collisionForce *  30.0f * deltaTime;
-                    _velocity                += collisionForce * 100.0f * deltaTime;
-                    _joint[b].springyPosition = position + directionVector * combinedRadius;
+                    _joint[b].springyVelocity += collisionForce * 0.0f * deltaTime;
+                    _velocity                 += collisionForce * 40.0f * deltaTime;
+                    _joint[b].springyPosition  = position + directionVector * combinedRadius;
                 }
             }
         }
@@ -1292,7 +1298,7 @@ void Avatar::updateBodySprings( float deltaTime ) {
             _joint[b].springyVelocity = glm::vec3( 0.0f, 0.0f, 0.0f );
         }
         
-        _joint[b].springyPosition += _joint[b].springyVelocity;
+        _joint[b].springyPosition += _joint[b].springyVelocity * deltaTime;
     }
 }
 
diff --git a/interface/src/Util.cpp b/interface/src/Util.cpp
index 50a9e8099f..436a52e7d3 100644
--- a/interface/src/Util.cpp
+++ b/interface/src/Util.cpp
@@ -245,12 +245,14 @@ void renderDiskShadow(glm::vec3 position, glm::vec3 upDirection, float radius, f
     glColor4f( 0.0f, 0.0f, 0.0f, darkness );
     
     int   num = 20;
-    float y  = 0.01f;
+    float y  = 0.001f;
     float x2 = 0.0f;
     float z2 = radius;
     float x1;
     float z1;
 
+    glBegin(GL_TRIANGLES);             
+
     for (int i=1; i<num+1; i++) {
         x1 = x2;
         z1 = z2;
@@ -258,12 +260,12 @@ void renderDiskShadow(glm::vec3 position, glm::vec3 upDirection, float radius, f
         x2 = radius * sin(r);
         z2 = radius * cos(r);
     
-        glBegin(GL_TRIANGLES);             
             glVertex3f(position.x,      y, position.z     ); 
             glVertex3f(position.x + x1, y, position.z + z1); 
             glVertex3f(position.x + x2, y, position.z + z2); 
-        glEnd();
     }
+    
+    glEnd();
 }
 
 
diff --git a/interface/src/main.cpp b/interface/src/main.cpp
index fdfcab934f..8780d9ed92 100644
--- a/interface/src/main.cpp
+++ b/interface/src/main.cpp
@@ -1015,7 +1015,7 @@ void display(void)
             float firstPersonTightness = 100.0f;
 
             float thirdPersonPitch     =   0.0f;
-            float thirdPersonUpShift   =  -0.1f;
+            float thirdPersonUpShift   =  -0.2f;
             float thirdPersonDistance  =   1.2f;
             float thirdPersonTightness =   8.0f;