Understanding the math behind 0x5f3759df and the fast inverse square root (2012)
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HN comment orderBe sure to read the appendix, which is an easy-to-miss link at the end: http://h14s.p5r.org/2012/09/0x5f3759df-appendix.html The appendix was by far the most interesting part to me, after reading it I felt like I really got the intuition behind how the trick works.
If anyone wants a fast atan2 that I wrote a while ago (2007), for making a microcontroller navigate, it's at http://robots-everywhere.com/portfolio/math/
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- Breakout years
- 2
- Total points
- 450
- Total comments
- 56
100+ points or 50+ comments
reference only — not used in Hall rules or ranking
reference only — not used in Hall rules or ranking
Every submission
| Date | Title as submitted | By | Points | Comments |
|---|---|---|---|---|
| 2014-10-28 | 0x5f3759df and the fast inverse square root (2012)First breakout | carljoseph | 125 | 25 |
| 2015-03-27 | Fast inverse square-root hack with magic constant 0x5f3759df (2012) | shreyassaxena | 46 | 5 |
| 2015-07-14 | The magic of the fast inverse square root (2012) | timdierks | 41 | 7 |
| 2016-10-25 | 0x5f3759df: 1/sqrt(x) | wyldfire | 3 | 0 |
| 2016-12-14 | 0x5f3759df | mmedal | 6 | 0 |
| 2017-08-15 | Fast inverse square root and the constant 0x5f3759df (2012) | siboehm | 1 | 0 |
| 2017-08-16 | Understanding the math behind 0x5f3759df and the fast inverse square root (2012)Best thread · Latest 20+ point return | ColinWright | 222 | 19 |
| 2020-02-01 | Quake 3's Fast Inverse Square Root | bbody | 4 | 0 |
| 2022-08-06 | Why 0x5f3759df? (2012) | Jimmc414 | 2 | 0 |