Differences

This shows you the differences between two versions of the page.

--- general [2020/04/10 18:32]
paul [Rotations]
+++ — (current)
@@ Line 1: / Line 1: @@
-====== General ======
-===== Rotations =====
-Unity uses 3 rotation systems. [[https://www.youtube.com/watch?v=kYOtk5a6_x4|Intro to Quaternion Rotations (in Unity)]]
-  - Euler Angers - rotation about x, y, z axis
-  - Angle Axis - A normalized Vector3 representing the axis about which to rotate by float angle amount
-  - Quaternions - Angle Axis rotation representation that have been scaled to improve performance.
-==== Calculations ====
-<code c#>
-// Get the direction to a camera
-Vector3 directionToCamera = Camera.main.transform.position - transform.position;
-transform.rotation = Quaternion.FromToRotation(Vector3.back, directionToCamera);
-</code>
-==== Quaternions ====
-They are in the form of ''x, y, z, w''. They are always normalized, so ''x² + y² + z² + w² = 0''
-=== Creating Quaternions ===
-<code c#>
-// This has to be normalized. We generally never use this
-Quaternion rotation = new Quaternion(0,0,0,1);
-// You usually create a rotation in euler and then convert to quaternion.
-==== Convertions ====
-<code c#>
-// Convert from Quaternion to Euler:
-Vector3 inEuler = quaternionRotation.eulerAngles;
-// Convert Euler to Quaternion
-Quaternion inQuaternion = Quaternion.Euler(inEuler);
-// To Angle-Axis
-Quaternion randomQuaternion = Random.rotation;
-float angle;
-Vector3 axis;
-randomQuaternion.ToAngleAxis(out angle, out axis);
-// And back
-Quaternion rotation = Quaternion.AngleAxis(angle,axis);
-</code>