Why float.Epsilon And Not Zero In Unity – In Unity (and in many programming contexts), float.Epsilon
is used instead of 0
when dealing with floating-point comparisons to avoid issues related to precision errors and the representation of very small numbers. Here’s why float.Epsilon
is preferred over 0
in such scenarios:
Understanding float.Epsilon
:
- Definition:
float.Epsilon
is the smallest positive number that is greater than zero and can be represented by afloat
data type. In C#, it is defined as1.401298E-45
.
Precision Issues with Floating-Point Numbers:
- Floating-Point Representation: Floating-point numbers in computers are represented with limited precision (typically 32 or 64 bits). This means not all real numbers can be represented exactly, especially very small numbers close to zero or very large numbers.
- Comparison Issues: Due to precision limitations, direct comparison of floating-point numbers with
0
using equality (==
) can lead to unexpected results. For example, a calculation that should result in0
might yield a number slightly above or below zero due to rounding errors.
Use Cases for float.Epsilon
:
-
Equality Comparisons: When checking if a floating-point value is approximately zero, you should use a comparison against
float.Epsilon
: