Hello,

Currently i represent a orientation in R³ through a quaternion q.
I want to set q through a front and up vector.
They are both unit vectors and perpendicular.

A orientation with a identity quaternion (no rotation) should be

front = Vector3f::UnitX();
up = Vector3f::UnitZ();

Iam searching for a function (without trigo stuff..) who does somethink like this:

Quaternion q;
set_quaternion(&q, front_vec, up_vec);

I would appreciate some help very much!

greetings Benni

you need to assemble the complete basis and assign it to the quaternion:

Code: Select all

Quaternionf q;
Matrix3f rot;
rot << front, up.cross(front), up;
q = rot;


Thank you!

Thats it.