Here's the short version: multiply your source vector by a 3d rotation matrix. Zaxo's snippet is nifty, but not quite sufficient as it doesn't do matrix math.
The extra complexity that comes with moving from 2d rotations to 3d rotations is the fact that, in 3d, you don't really have a canonical axis to rotate around. In the x-y plane, when you do a rotation by r radians, you pretty much have to rotate around the z axis. In 3d space, you can rotate around the x, y, or z axis, or around an arbitrary vector (if that gives you problems, think of it as rotating around several canonical axes at once). So you can't easily describe a 3d rotation with a single parameter; you basically need a matrix (or a quaternion, but let's not go there).
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:
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
- 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
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.
| & || & |
| < || < |
| > || > |
| [ || [ |
| ] || ] ||