Subject:
|
3D geometry question
|
Newsgroups:
|
lugnet.cad
|
Date:
|
Wed, 13 Oct 1999 09:46:22 GMT
|
Viewed:
|
511 times
|
| |
|
|
Hi, I have this problem I hope someone may solve.
Say I have a vector v with length normalized to 1. For simplicity,
picture this vector as starting in the origin. Now, I need a
rotation matrix M with the following properties:
o If I rotate a part with one edge going from (0,0,0) to (0,-1,0)
(i.e., pointing upwards), this edge should coincide with the vector v
after the transformation
o M should be a proper transformation, i.e., no scaling or shearing.
Thanks for any help!
Fredrik
|
|
Message has 2 Replies:
 | | Re: 3D geometry question
|
| Fredrik Glöckner: (...) Vectors don't start anywhere. A vector is just a direction and a length. (...) Lets call the vector along the edge e. (...) There are infinitely many solutions to the problem. When you have one solution, any rotation around v (...) (25 years ago, 13-Oct-99, to lugnet.cad)
| | | Re: 3D geometry question
|
| Fredrik Glöckner skrev i meddelandet ... (...) What about: Assume V = (Vx, Vy, Vz) B = arctan(Vx/Vz) (Better with arctan2(Vz, Vx) if available, otherwise you have to adjust to the right quadrant manually) Matrix for rotation around Y: ( cos(B) 0 (...) (25 years ago, 13-Oct-99, to lugnet.cad)
|
7 Messages in This Thread:
  
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
