(adsbygoogle = window.adsbygoogle || []).push({}); An Example Scenario:

A particle moves at 32° and collides with a wall. This wall is rectangular in nature, which means that there is both horizontal and vertical sides.

On a horizontal tangent, it would work like this (sorry for ugly, not-to-scale diagrams):

[PLAIN]http://img198.imageshack.us/img198/7808/questionsc.jpg [Broken]

(reflects at 148°)

However, on a vertical tangent it would reflect like this:

[PLAIN]http://img808.imageshack.us/img808/2064/question2.png [Broken]

(reflects at 328°)

This means that:

- On horizontal tangent: reflectionDirection = 180-incidenceDirection
- On vertical tangent: reflectionDirection = 360-incidenceDirection

It's lame to have two different formulas, so is there a general formula for the reflectionDirection that works with both vertical and horizontal tangents? It's fine if it uses radians instead of degrees.

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# General Formula For Reflection Direction

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