# Slerping

Hi all,

Can anyone explain Quaternion slerping to me please? and what it does?

I sorta cant find a website that explains it to me.

Thx a zillion, DP

Very short here: A line can linearly interpolate from one point to the other. Easy no nonsense there.

A circle is different. A point on a circlecan be represented by theta. The theta is an angel. It starts at 0 and goes to 360 and restarts. If you draw out the geometry of a circle,

Y=sin(theta)

X=cos(theta)

If you’re lost draw a circle with a triangle inside it, starting at the origin and try to calculate the length sides of the triangle. Or just keep reading

The idea for slerp comes from the fact that sin and cos are not linear graphs. Ever graphed the function Y=cos(x)? It’s a curve. This presents a problem though. You can’t just linearly interpolate Y values for a rotation because they follow a curved path. Slerp is a “curved” movement along the sphere. At least that’s the idea.

Quaternions are rotations. Going from one rotation to another requires you to move along that “curved” spherical path.

Thx cep21

DP