lisyarus/psemek
1
0
Fork 1
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Use faster quaternion rotation formula

Browse source
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
Show stats Download patch file Download diff file Expand all files Collapse all files

6
libs/geom/include/psemek/geom/quaternion.hpp
View file

@ -213,8 +213,10 @@ namespace psemek::geom
template <typename T>
vector<T, 3> rotate(quaternion<T> const & q, vector<T, 3> const & v)
{
auto res = q * quaternion<T>::vector(v) * conjugate(q);
return {res[0], res[1], res[2]};
// 2x faster than q*v*cong(q), see https://www.johndcook.com/blog/2021/06/16/faster-quaternion-rotations/
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>