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Use faster quaternion rotation formula

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This commit is contained in:
Nikita Lisitsa 2024-02-28 16:59:29 +03:00
parent 540d63ce5b
commit 84ef3faa68
1 changed files with 4 additions and 2 deletions
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6
libs/geom/include/psemek/geom/quaternion.hpp
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@ -213,8 +213,10 @@ namespace psemek::geom
template <typename T> template <typename T>
vector<T, 3> rotate(quaternion<T> const & q, vector<T, 3> const & v) vector<T, 3> rotate(quaternion<T> const & q, vector<T, 3> const & v)
{ {
auto res = q * quaternion<T>::vector(v) * conjugate(q); // 2x faster than q*v*cong(q), see https://www.johndcook.com/blog/2021/06/16/faster-quaternion-rotations/
return {res[0], res[1], res[2]}; auto qv = vector{q[0], q[1], q[2]};
auto t = T(2) * cross(qv, v);
return v + q[3] * t + cross(qv, t);
} }
template <typename T> template <typename T>