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**Modification Help / Re: How do I rotate an axis-angle around a normal vector?**

« **on:**May 16, 2018, 08:24:35 AM »

I don't know if you're still having this issue or want it solved, but axis-angle rotations are very simple, so I'll explain them for you.

They consist of two parts: a vector and a length (or angle, if you prefer). The vector is the normal to the disc you want to rotate in (in this case, you already have the normal to the plane the object is sitting on), and the length (angle) is equal to the rotation in radians you want to perform. In this case, the angle is the only thing left for you to calculate. Simply normalize the blue vector in the image you provided, then append a fourth number with the angle of rotation. You could probably calculate the angle of rotation by using the direction that the normal is pointing in.

They consist of two parts: a vector and a length (or angle, if you prefer). The vector is the normal to the disc you want to rotate in (in this case, you already have the normal to the plane the object is sitting on), and the length (angle) is equal to the rotation in radians you want to perform. In this case, the angle is the only thing left for you to calculate. Simply normalize the blue vector in the image you provided, then append a fourth number with the angle of rotation. You could probably calculate the angle of rotation by using the direction that the normal is pointing in.