From b2e02e20ccf675d2359267b4fa2b122613137be1 Mon Sep 17 00:00:00 2001
From: luiscuenca <luiscuenca@outboxcode.com>
Date: Thu, 5 Jul 2018 11:47:10 -0700
Subject: [PATCH] Fix inaccurate delta rotation axis

---
 libraries/physics/src/CharacterController.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libraries/physics/src/CharacterController.cpp b/libraries/physics/src/CharacterController.cpp
index 64eda975cf..bb076c89f2 100755
--- a/libraries/physics/src/CharacterController.cpp
+++ b/libraries/physics/src/CharacterController.cpp
@@ -269,7 +269,8 @@ void CharacterController::playerStep(btCollisionWorld* collisionWorld, btScalar
         }
         btQuaternion deltaRot = desiredRot * startRot.inverse();
         float angularSpeed = deltaRot.getAngle() / _followTimeRemaining;
-        btQuaternion angularDisplacement = btQuaternion(deltaRot.getAxis(), angularSpeed * dt);
+        glm::vec3 rotationAxis = glm::normalize(glm::axis(bulletToGLM(deltaRot)));  // deltaRot.getAxis() is inaccurate
+        btQuaternion angularDisplacement = btQuaternion(glmToBullet(rotationAxis), angularSpeed * dt);
         btQuaternion endRot = angularDisplacement * startRot;
 
         // in order to accumulate displacement of avatar position, we need to take _shapeLocalOffset into account.