Smoothly interpolates between two vectors or quaternions using spherical linear interpolation (slerp). Unlike regular linear interpolation, slerp follows the shortest path along a curve, which keeps the motion smooth and even. This makes it a good choice for blending between rotations or directions.
vector2 slerp(vector2 x, vector2 y, float a)
vector3 slerp(vector3 x, vector3 y, float a)
vector4 slerp(vector4 x, vector4 y, float a)
quat slerp(quat x, quat y, float a)
x.0.0 and 1.0.A value of the same type as x and y. When a is 0.0 the result equals x, when a is 1.0 the result
equals y, and values in between blend smoothly from x to y.
-- Interpolate halfway between two vector3 directions:
local v1 = vector3(1, 0, 0) -- right
local v2 = vector3(0, 1, 0) -- up
print(slerp(v1, v2, 0.5)) -- halfway between right and up
-- At the boundaries:
print(slerp(v1, v2, 0.0)) -- prints `vector3(1, 0, 0)` (equals v1)
print(slerp(v1, v2, 1.0)) -- prints `vector3(0, 1, 0)` (equals v2)
-- Works with quaternions for smooth rotation interpolation:
local q1 = quat(0, vector3(0, 0, 1)) -- no rotation
local q2 = quat(90, vector3(0, 0, 1)) -- 90 degrees around Z
local qMid = slerp(q1, q2, 0.5) -- 45 degrees around Z
-- Works with vector2:
local v1 = vector2(1, 0)
local v2 = vector2(0, 1)
print(slerp(v1, v2, 0.5))Smoothly rotate a vehicle towards a target rotation over time:
local vehicle = GetVehiclePedIsIn(PlayerPedId())
local x, y, z, w = GetEntityQuaternion(vehicle)
local currentRot = quat(w, x, y, z)
local targetRot = quat(90, vector3(0, 0, 1))
-- Interpolate 10% of the way towards the target each frame:
local newRot = slerp(currentRot, targetRot, 0.1)
SetEntityQuaternion(vehicle, newRot.x, newRot.y, newRot.z, newRot.w)