# Lerp between euler angles?

does anyone know how I’d lerp between two 3d euler rotations in a plugin?

I need to find the rotation in the ‘middle’

http://www.euclideanspace.com/maths/algebra/realNormedAlgebra/quaternions/slerp/
and why you would want to use quaternions:

euler to quaternion is simple: use axis-angle notation defining axis vectors as the axis of rotation
http://www.euclideanspace.com/maths/geometry/rotations/conversions/angleToQuaternion/

you won’t be able to get back euler rotation though just through decomposing a matrix calculated from quaternion, but who needs euler if you have quaternions ;)

shorthand is, quaternions are computationally a better fit to most spherical problems. two features come with quaternions:

• rotation can be done with addition, instead of the expensive sine trigonometry
• they avoid the singularity issues of eulers at the poles

once you find a handle on the weird 4d part, it can help save your day many days

euler angles are so 90ies… halfway serious but then quite funny on a closer look.

actually i never quite understood how this weird triple complex number thingy with “i^2 = j^2 = k^2 = ijk = -1” led to points on the 3-sphere and rotating objects but i sense for a practical level you don’t have to 100% understand that

so mrboni, use an euler to quaternion method from a slimdx or so and use Slerp with 0.5 as interpolation value. you can then get the rotation matrix from the quaternion if needed.

thanks guys

I suspected as much

Stuck in my 90s ways I am

Time to embrace the quaternions