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Add vector.axis_angle3

master
Lars Mueller 2022-06-17 11:15:47 +02:00
parent c14c208a61
commit f3d856c2db
1 changed files with 13 additions and 0 deletions
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13
vector.lua
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@ -194,6 +194,19 @@ function angle(v, w)
return math.acos(dot(v, w) / length(v) / length(w))
end
-- See https://www.euclideanspace.com/maths/geometry/rotations/conversions/eulerToAngle/
function axis_angle3(euler_rotation)
assert(#euler_rotation == 3)
euler_rotation = divide_scalar(euler_rotation, 2)
local cos = apply(euler_rotation, math.cos)
local sin = apply(euler_rotation, math.sin)
return normalize_zero{
sin[1] * sin[2] * cos[3] + cos[1] * cos[2] * sin[3],
sin[1] * cos[2] * cos[3] + cos[1] * sin[2] * sin[3],
cos[1] * sin[2] * cos[3] - sin[1] * cos[2] * sin[3],
}, 2 * math.acos(cos[1] * cos[2] * cos[3] - sin[1] * sin[2] * sin[3])
end
-- Uses Rodrigues' rotation formula
-- axis must be normalized
function rotate3(v, axis, angle)