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Unity 5  Game Optimization

You're reading from   Unity 5 Game Optimization Master performance optimization for Unity3D applications with tips and techniques that cover every aspect of the Unity3D Engine

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Product type Paperback
Published in Nov 2015
Publisher Packt
ISBN-13 9781785884580
Length 296 pages
Edition 1st Edition
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Chris Dickinson Chris Dickinson
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Chris Dickinson
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Table of Contents (10) Chapters Close

Consider using distance-squared over distance


It is safe to say that CPUs are relatively good at multiplying floating-point numbers together, but relatively dreadful at calculating square roots from them. Every time we ask a Vector3 to calculate a distance with the magnitude property or with the Distance() method, we're asking it to perform a square root calculation (as per the Pythagorean theorem), which can cost a lot of CPU overhead compared to many other types of vector math calculations.

However, the Vector3 class also offers a sqrMagnitude property, which is the same as distance, only squared. This lets us perform essentially the same comparison check without the expensive square root included, so long as we also square the value we're trying to compare it against; or, to describe this mathematically, if the magnitude of A is less than the magnitude of B, then A2 will be less than B2.

For example, consider code like the following:

float distance = (transform.position – other.transform...
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