Modern Math Slerp

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Slerp

Blends between two rotations at constant speed, taking the shorter way round.

Syntax

Slerp( byref a as Quat, byref b as Quat, byval t as float32 ) as Quat

Notes

• Constant angular velocity -- which a component-wise Lerp between quaternions does not give, and that difference is visible as a rotation that speeds up in the middle.
• t runs 0 to 1 and is not clamped.
• It takes the shorter arc: if the two rotations are more than 180 degrees apart it negates one first, because a quaternion and its negation are the same rotation.

Examples

#import "std/numeric"
using numeric

dim as Quat a = type<Quat>( 0, 0, 0, 1 )
dim as Quat b = type<Quat>( 0, 0, 0, 1 )

dim as Quat h = Slerp( a, b, 0.5 )
print h.w                    '' 1

'' Constant angular velocity is the whole point: a component-wise Lerp
'' between rotations speeds up in the middle

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Library: Math Library
Category: Math Library
Documented under: Members