Efficiently Building a Matrix to Rotate One Vector to Another

Tomas Möller
Chalmers University of Technology

This paper appears in issue Volume 4, Number 4.
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Abstract

We describe an efficient (no square roots or trigonometric functions) method to construct the 3×3 matrix that rotates a unit vector f into another unit vector t, rotating about the axis f×t. We give experimental results showing this method is faster than previously known methods. An implementation in C is provided.

Author Information

Tomas Möller, Chalmers University of Technology, Dept of Computer Engineering412 96 Gothenburg, Sweden tompa@acm.org

John F. Hughes, Brown University, Computer Science Department, 115 Waterman Street, Providence, RI 02912 jfh@cs.brown.edu

Follow-up

[May, 2003] The computation of h described on page 2 can be further optimized:

h = (1-c)/(1-c*c) = (1-c)/(v.v) = 1/(1+c)

Thanks to Gottfried Chen for pointing this out.

Source Code

The following C source file contains an implementation of the algorithm described in the paper, including the above optimization: fromtorot.c (3K HTML text)

BibTeX Entry

@article{MollerHughes99,
  author = "Tomas Möller and John F. Hughes",
  title = "Efficiently Building a Matrix to Rotate One Vector to Another",
  journal = "journal of graphics, gpu, and game tools",
  volume = "4",
  number = "4",
  pages = "1-4",
  year = "1999",
}