Values under 0 will be clamped by Color structure.

If you use cos or sin there half of lenght it will pulse others not.

If you want to pulse with pause try:

```
math.abs( math.cos( RealTime()*frequency )*waveLenght ) )
```

it will be positive everytime (0 is lowest)

Also try not completed fade:

```
local alpha = 127 + math.cos( RealTime()*frequency )*waveLenght
```

it will pulse from 127+waveLength to 127-waveLenght

This is useful when you need a fade but save visibility.

The first code with

math.abs almost same as:

```
local alpha = 127 + math.cos( RealTime()*frequency )*127
```

The fade will be from 127+127 (254 in total) to 127-127 (0 in total)

**Examples: **

Fades of (0,0,0) on (255,255,255)

Numbers of alpha was rounded

**1.** math.cos(CurTime()*2)*255

**2.** math.abs(math.cos(CurTime()*2)*255)

**3.** 127+math.cos(CurTime()*2)*50

**4.** math.abs(math.sin(CurTime()*2)*255)