Convert CGAffineTransform to rotate a sprite

[UncleAcid]

Hi,

I have several XML animations that involve rotating a sprite and the animation is using CGAffineTransform (it's from the iOS source for a port I'm working on), and I can't figure out how to convert those 4 numbers into correct Z rotation for NGUI. I've gotten my sprite to rotate but it's not right (for example; should rotate 360 but kinda rocks back and forth). Any help is greatly appreciated, thanks.

Example of one of the frames:

1. <array>
2.     <real>0.366912841796875</real>
3.     <real>-0.929046630859375</real>
4.     <real>0.929046630859375</real>
5.     <real>0.366912841796875</real>
6. </array>
7.  

and my reading code:

1. List<object> transformMatrix = (List<object>)frameAction["setTransform"];
2.                                        
3. float a = (float)(double)transformMatrix[0];
4. float b = (float)(double)transformMatrix[1];
5. float c = (float)(double)transformMatrix[2];
6. float d = (float)(double)transformMatrix[3];
7.  
8. item.cachedTransform.rotation = new Quaternion(); // What goes here ?
9.  

[ArenMook]

I have no idea what CGAffineTransform is, or those 4 values mean. 4 values generally imply either a Vector4, or a Quaternion. A matrix has 16 values. I can't be of much help here as it's not an NGUI question at all. Even setting the rotation of something is a Unity question. I will say this though -- you should be setting transform.localRotation, not world rotation that you're setting now.

[Nicki]

From the looks of the values, it could be quaternions, but it's all a bit of dark magic to me.

Take a look at https://docs.unity3d.com/Documentation/ScriptReference/Quaternion.html

And set the local rotation so it's set in relation to the hierarchy.

[ArenMook]

The thing about quaternions is that they differ if the coordinate system is left-handed vs right-handed.