SA.FullBodyIK.HeadIK.Solve C# (CSharp) Method

			public bool Solve( FullBodyIK fullBodyIK )
			{
				if( _neckBone == null || !_neckBone.transformIsAlive ||
					_headBone == null || !_headBone.transformIsAlive ||
					_headBone.parentBone == null || !_headBone.parentBone.transformIsAlive ) {
					return false;
				}

				_SyncDisplacement( fullBodyIK );

				float headPositionWeight = _headEffector.positionEnabled ? _headEffector.positionWeight : 0.0f;
				float eyesPositionWeight = _eyesEffector.positionEnabled ? _eyesEffector.positionWeight : 0.0f;

				if( headPositionWeight <= IKEpsilon && eyesPositionWeight <= IKEpsilon ) {
					Quaternion parentWorldRotation = _neckBone.parentBone.worldRotation;
					Quaternion parentBaseRotation;
					SAFBIKQuatMult( out parentBaseRotation, ref parentWorldRotation, ref _neckBone.parentBone._worldToBaseRotation );

					if( _internalValues.resetTransforms ) {
						Quaternion tempRotation;
						SAFBIKQuatMult( out tempRotation, ref parentBaseRotation, ref _neckBone._baseToWorldRotation );
						_neckBone.worldRotation = tempRotation;
					}

					float headRotationWeight = _headEffector.rotationEnabled ? _headEffector.rotationWeight : 0.0f;
					if( headRotationWeight > IKEpsilon ) {
						Quaternion headEffectorWorldRotation = _headEffector.worldRotation;
                        Quaternion toRotation;
						SAFBIKQuatMult( out toRotation, ref headEffectorWorldRotation, ref _headEffectorToWorldRotation );
						if( headRotationWeight < 1.0f - IKEpsilon ) {
							Quaternion fromRotation;
							if( _internalValues.resetTransforms ) {
								SAFBIKQuatMult( out fromRotation, ref parentBaseRotation, ref _headBone._baseToWorldRotation );
                            } else {
								fromRotation = _headBone.worldRotation; // This is able to use _headBone.worldRotation directly.
							}
							_headBone.worldRotation = Quaternion.Lerp( fromRotation, toRotation, headRotationWeight );
						} else {
							_headBone.worldRotation = toRotation;
						}

						_HeadRotationLimit();
					} else {
						if( _internalValues.resetTransforms ) {
							Quaternion tempRotation;
							SAFBIKQuatMult( out tempRotation, ref parentBaseRotation, ref _headBone._baseToWorldRotation );
							_headBone.worldRotation = tempRotation;
                        }
					}

					if( _internalValues.resetTransforms ) {
						if( _isEnabledCustomEyes ) {
							fullBodyIK._ResetCustomEyes();
						} else {
							_ResetEyes();
						}
					}

					return _internalValues.resetTransforms || (headRotationWeight > IKEpsilon);
				}

				_Solve( fullBodyIK );
				return true;
			}