Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl-Sensitive Sunglasses
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
To find the angle between the two vectors, you need to normalize them (so they have length of 1 unit) by doing this (v is the vector you want to normalize):
float distance = sqrt(v.x*v.x + v.y*v.y + v.z*v.z); v.x = v.x/distance; v.y = v.y/distance; v.z = v.z/distance;
Then find the dot product of the two normalized vectors (Va and Vb):
float dotProduct = Va.x*Vb.x + Va.y*Vb.y + Va.z*Vb.z;
This gives you the cosine of the angle, so simple do:
acos(dotProduct);
This will give you the angle. I think this post was a bit late :S

In reply to Re^3: Rotate a 3D vector by Anonymous Monk
in thread Rotate a 3D vector by true

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others browsing the Monastery: (4)
    As of 2020-12-04 05:47 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      How often do you use taint mode?





      Results (58 votes). Check out past polls.

      Notices?