more prep for shifting avatar during HMD motion

interface/src/avatar/MyAvatar.cpp

@@ -114,7 +114,6 @@ MyAvatar::MyAvatar(RigPointer rig) :
     ,_hmdAtRestDetector(glm::vec3(0), glm::quat())
 #else
     ,_avatarOffsetFromHMD(0.0f)
-    ,_hmdVelocity(0.0f)
 #endif  // OLD_HMD_TRACKER
 {
     for (int i = 0; i < MAX_DRIVE_KEYS; i++) {
@@ -375,9 +374,16 @@ void MyAvatar::updateFromHMDSensorMatrix(const glm::mat4& hmdSensorMatrix) {
     }
 
     followHMD(deltaTime);
+#else
+    // TODO adebug BOOKMARK -- this is where we need to add the new code for HMD_TRACKER
 #endif  // OLD_HMD_TRACKER
 }
 
+glm::vec3 MyAvatar::getHMDCorrectionVelocity() const {
+    // TODO: impelement this
+    return Vectors::ZERO;
+}
+
 #ifdef OLD_HMD_TRACKER
 void MyAvatar::beginFollowingHMD() {
     // begin homing toward derived body position.
@@ -433,10 +439,6 @@ void MyAvatar::followHMD(float deltaTime) {
             _bodySensorMatrix = createMatFromQuatAndPos(rot, pos);
         }
     }
-}
-#else
-void MyAvatar::harvestHMDOffset(glm::vec3 offset) {
-    
 }
 #endif // USE_OLD
 
@@ -1292,7 +1294,7 @@ void MyAvatar::prepareForPhysicsSimulation() {
     relayDriveKeysToCharacterController();
     _characterController.setTargetVelocity(getTargetVelocity());
     _characterController.setAvatarPositionAndOrientation(getPosition(), getOrientation());
-    //_characterController.setHMDVelocity(hmdVelocity);
+    _characterController.setHMDVelocity(getHMDCorrectionVelocity());
 }   
 
 void MyAvatar::harvestResultsFromPhysicsSimulation() {
@@ -1301,6 +1303,9 @@ void MyAvatar::harvestResultsFromPhysicsSimulation() {
     _characterController.getAvatarPositionAndOrientation(position, orientation);
     nextAttitude(position, orientation);
     setVelocity(_characterController.getLinearVelocity());
+    
+    // adebug TODO: harvest HMD shift here
+    //glm::vec3 hmdShift = _characterController.getHMDShift();
 }
 
 QString MyAvatar::getScriptedMotorFrame() const {

interface/src/avatar/MyAvatar.h

@@ -76,6 +76,8 @@ public:
     // as it moves through the world.
     void updateFromHMDSensorMatrix(const glm::mat4& hmdSensorMatrix);
 
+    glm::vec3 getHMDCorrectionVelocity() const;
+
     // best called at end of main loop, just before rendering.
     // update sensor to world matrix from current body position and hmd sensor.
     // This is so the correct camera can be used for rendering.
@@ -272,8 +274,6 @@ private:
     void beginFollowingHMD();
     bool shouldFollowHMD() const;
     void followHMD(float deltaTime);
-#else
-    void harvestHMDOffset(glm::vec3 offset);
 #endif
 
     bool cameraInsideHead() const;
@@ -376,7 +376,6 @@ private:
     bool _lastIsMoving { false };
 #else
     glm::vec3 _avatarOffsetFromHMD;
-    glm::vec3 _hmdVelocity;
 #endif // OLD_HMD_TRACKER
 };
 

interface/src/avatar/MyCharacterController.cpp

@@ -16,7 +16,6 @@
 #include <BulletCollision/CollisionDispatch/btCollisionWorld.h>
 #include <LinearMath/btDefaultMotionState.h>
 
-#include <BulletUtil.h>
 #include <GLMHelpers.h>
 #include <PhysicsLogging.h>
 #include <PhysicsCollisionGroups.h>
@@ -161,6 +160,17 @@ void MyCharacterController::playerStep(btCollisionWorld* dynaWorld, btScalar dt)
             _rigidBody->setLinearVelocity(actualVelocity + tau * velocityCorrection);
         }
     }
+
+    // Rather than add _hmdVelocity to the velocity of the RigidBody, we explicitly teleport 
+    // the RigidBody forward according to the formula: distance = rate * time
+    if (_hmdVelocity.length2() > 0.0f) {
+        btTransform bodyTransform = _rigidBody->getWorldTransform();
+        bodyTransform.setOrigin(bodyTransform.getOrigin() + dt * _hmdVelocity);
+        _rigidBody->setWorldTransform(bodyTransform);
+    }
+    // MyAvatar will ask us how far we stepped for HMD motion, which will depend on how 
+    // much time has accumulated in _lastStepDuration.
+    _lastStepDuration += dt;
 }
 
 void MyCharacterController::jump() {
@@ -390,6 +400,7 @@ void MyCharacterController::preSimulation() {
             }
         }
     }
+    _lastStepDuration = 0.0f;
 }
 
 void MyCharacterController::postSimulation() {

interface/src/avatar/MyCharacterController.h

@@ -16,6 +16,7 @@
 #include <btBulletDynamicsCommon.h>
 #include <glm/glm.hpp>
 
+#include <BulletUtil.h>
 #include <CharacterController.h>
 #include <SharedUtil.h>
 
@@ -48,7 +49,6 @@ public:
     // overrides from CharacterController
     virtual void preSimulation() override;
     virtual void postSimulation() override;
-    virtual void incrementSimulationTime(btScalar timeStep) override { _lastStepDuration += timeStep; }
 
     bool isHovering() const { return _isHovering; }
     void setHovering(bool enabled);
@@ -65,6 +65,7 @@ public:
 
     void setTargetVelocity(const glm::vec3& velocity);
     void setHMDVelocity(const glm::vec3& velocity);
+    glm::vec3 getHMDShift() const { return _lastStepDuration * bulletToGLM(_hmdVelocity); }
 
     glm::vec3 getLinearVelocity() const;
 

libraries/physics/src/CharacterController.h

@@ -36,7 +36,6 @@ public:
 
     virtual void updateShapeIfNecessary() = 0;
     virtual void preSimulation() = 0;
-    virtual void incrementSimulationTime(btScalar stepTime) = 0;
     virtual void postSimulation() = 0;
 
     virtual void setWalkDirection(const btVector3 &walkDirection) { assert(false); }