CMCL-710: 3rd person gimbal lock fix (#370)

* eliminate 3rdpersonFollow console spam when looking up or down

* revert a too-aggressive change

* too aggressive again

Author: glabute

CHANGELOG.md

@@ -15,8 +15,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Regression fix: compilation errors when physics module is not present.
 - GameObjects created with Gameobject menu items now follow Unity naming conventions.
 - Regression fix: virtual cameras no longer forget that they are targeting groups on domain reload.
+- Moved Cinemachine tools into the main Tools overlay (2022.1+), moved Freelook rig selection to a separate overlay, updated icons to support light and dark themes.
+- Bugfix: 3rdPersonFollow logged console messages when looking straight up or down.
 - BugFix: InputProvider no longer causes a tiny gc alloc every frame.
-- Moved Cinemachine tools into the main Tools overlay (2022.1+), moved Freelook rig selection to a separate overlay, updated icons to support light and dark themes
 
 
 ## [2.9.0-pre.1] - 2021-10-26

Editor/Editors/Cinemachine3rdPersonFollowEditor.cs

@@ -68,11 +68,11 @@ void DrawSceneTools()
                     out var armPosition);
                 var followTargetRotation = thirdPerson.FollowTargetRotation;
                 var targetForward = followTargetRotation * Vector3.forward;
+                var heading = Cinemachine3rdPersonFollow.GetHeading(
+                    followTargetRotation, thirdPerson.VirtualCamera.State.ReferenceUp);
 
                 EditorGUI.BeginChangeCheck();
                 // shoulder handle
-                var heading = Cinemachine3rdPersonFollow.GetHeading(
-                    targetForward, thirdPerson.VirtualCamera.State.ReferenceUp);
                 var sHandleMinId = GUIUtility.GetControlID(FocusType.Passive); // TODO: KGB workaround until id is exposed
                 var newShoulderPosition = Handles.PositionHandle(shoulderPosition, heading);
                 var sHandleMaxId = GUIUtility.GetControlID(FocusType.Passive); // TODO: KGB workaround until id is exposed

Runtime/Components/Cinemachine3rdPersonFollow.cs

@@ -186,7 +186,7 @@ void PositionCamera(ref CameraState curState, float deltaTime)
             var targetPos = FollowTargetPosition;
             var targetRot = FollowTargetRotation;
             var targetForward = targetRot * Vector3.forward;
-            var heading = GetHeading(targetForward, up);
+            var heading = GetHeading(targetRot, up);
 
             if (deltaTime < 0)
             {
@@ -234,8 +234,7 @@ public void GetRigPositions(out Vector3 root, out Vector3 shoulder, out Vector3
         {
             var up = VirtualCamera.State.ReferenceUp;
             var targetRot = FollowTargetRotation;
-            var targetForward = targetRot * Vector3.forward;
-            var heading = GetHeading(targetForward, up);
+            var heading = GetHeading(targetRot, up);
             root = m_PreviousFollowTargetPosition;
             GetRawRigPositions(root, targetRot, heading, out shoulder, out hand);
 #if CINEMACHINE_PHYSICS
@@ -244,10 +243,12 @@ public void GetRigPositions(out Vector3 root, out Vector3 shoulder, out Vector3
 #endif
         }
 
-        internal static Quaternion GetHeading(Vector3 targetForward, Vector3 up)
+        internal static Quaternion GetHeading(Quaternion targetRot, Vector3 up)
         {
-            var planeForward = targetForward.ProjectOntoPlane(up);
-            planeForward = Vector3.Cross(up, Vector3.Cross(planeForward, up));
+            var targetForward = targetRot * Vector3.forward;
+            var planeForward = Vector3.Cross(up, Vector3.Cross(targetForward.ProjectOntoPlane(up), up));
+            if (planeForward.AlmostZero())
+                planeForward = Vector3.Cross(targetRot * Vector3.right, up);
             return Quaternion.LookRotation(planeForward, up);
         }