# perspective()

The `perspective()` CSS function defines a transformation that sets the distance between the user and the z=0 plane, the perspective from which the viewer would be if the 2-dimensional interface were 3-dimensional. Its result is a `<transform-function>` data type.

The `perspective()` transform function is part of the `transform` value applied on the element being transformed. This differs from the `perspective` and `perspective-origin` properties which are attached to the parent of a child transformed in 3-dimensional space.

## Syntax

The perspective distance used by `perspective()` is specified by a `<length>` value, which represents the distance between the user and the z=0 plane. The z=0 plane is the plane where everything appears in a 2-dimensional view, or the screen. A positive value makes the element appear closer to the user than the rest of the interface, a negative value farther. The greater the value, the further away the perspective of the user is.

```perspective(d)
```

### Values

d
Is a `<length>` representing the distance from the user to the z=0 plane. If it is 0 or a negative value, no perspective transform is applied.
Cartesian coordinates on ℝ2 Homogeneous coordinates on ℝℙ2 Cartesian coordinates on ℝ3 Homogeneous coordinates on ℝℙ3

This transformation applies to the 3D space and can't be represented on the plane.

This transformation is not a linear transformation in ℝ3, and can't be represented using a Cartesian-coordinate matrix. $\left(\begin{array}{ccc}10& 0& 0\\ 01& 0& 0\\ 0& 0& 1& 0\\ 0& 0& -1/d& 1\end{array}\right)$

## Examples

### HTML

```<p>Without perspective:</p>
<div class="no-perspective-box">
<div class="face front">A</div>
<div class="face top">B</div>
<div class="face left">C</div>
</div>

<p>With perspective (9cm):</p>
<div class="perspective-box-far">
<div class="face front">A</div>
<div class="face top">B</div>
<div class="face left">C</div>
</div>

<p>With perspective (4cm):</p>
<div class="perspective-box-closer">
<div class="face front">A</div>
<div class="face top">B</div>
<div class="face left">C</div>
</div>
```

### CSS

```.face {
position: absolute;
width: 100px;
height: 100px;
line-height: 100px;
font-size: 100px;
text-align: center;
}

p + div {
width: 100px;
height: 100px;
transform-style: preserve-3d;
margin-left: 100px;
}
.no-perspective-box {
transform: rotateX(-15deg) rotateY(30deg);
}

.perspective-box-far {
transform: perspective(9cm) rotateX(-15deg) rotateY(30deg);
}

.perspective-box-closer {
transform: perspective(4cm) rotateX(-15deg) rotateY(30deg);
}

.top {
background-color: skyblue;
transform: rotateX(90deg) translate3d(0, 0, 50px);
}

.left {
background-color: pink;
transform: rotateY(-90deg) translate3d(0, 0, 50px);
}

.front {
background-color: limegreen;
transform: translate3d(0, 0, 50px);
}
```

## Specifications

Specification Status Comment
CSS Transforms Level 2
The definition of 'perspective()' in that specification.
Editor's Draft Initial definition

## Browser compatibility

Please see the `<transform-function>` data type for compatibility info.