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Transforms:

With CSS3 came new ways to position and alter elements. Now general layout techniques can be revisited with alternative ways to size, position, and change elements. All of these new techniques are made possible by the transform property.

The transform property comes in two different settings, two-dimensional and three-dimensional. Each of these come with their own individual properties and values.

Transform Syntax:

The actual syntax for the transform property is quite simple, including the transform property followed by the value. The value specifies the transform type followed by a specific amount inside parentheses.

2D Transforms:

Elements may be distorted, or transformed, on both a two-dimensional plane or a three-dimensional plane. Two-dimensional transforms work on the x and y axes, known as horizontal and vertical axes.

• 2D Rotate:

The transform property accepts a handful of different values. The rotate value provides the ability to rotate an element from 0 to 360 degrees.

• 2D Scale:

Using the scale value within the transform property allows you to change the appeared size of an element. The default scale value is 1, therefore any value between .99 and .01 makes an element appear smaller while any value greater than or equal to 1.01 makes an element appear larger.

• 2D Translate:

The translate value works a bit like that of relative positioning, pushing and pulling an element in different directions without interrupting the normal flow of the document. Using the translateX value will change the position of an element on the horizontal axis while using the translateY value will change the position of an element on the vertical axis.

• 2D Skew:

The last transform value in the group, skew, is used to distort elements on the horizontal axis, vertical axis, or both. The syntax is very similar to that of the scale and translate values. Using the skewX value distorts an element on the horizontal axis while the skewY value distorts an element on the vertical axis. To distort an element on both axes the skew value is used, declaring the x axis value first, followed by a comma, and then the y axis value.%p.

Combining Transforms:

It is common for multiple transforms to be used at once, rotating and scaling the size of an element at the same time for example. In this event multiple transforms can be combined together. To combine transforms, list the transform values within the transform property one after the other without the use of commas.

Transform Origin:

As previously mentioned, the default transform origin is the dead center of an element, both 50% horizontally and 50% vertically. To change this default origin position the transform-origin property may be used.

The transform-origin property can accept one or two values. When only one value is specified, that value is used for both the horizontal and vertical axes. If two values are specified, the first is used for the horizontal axis and the second is used for the vertical axis.

Perspective:

In order for three-dimensional transforms to work the elements need a perspective from which to transform. The perspective for each element can be thought of as a vanishing point, similar to that which can be seen in three-dimensional drawings.

The perspective of an element can be set in two different ways. One way includes using the perspective value within the transform property on individual elements, while the other includes using the perspective property on the parent element residing over child elements being transformed.

• Perspective Depth Value:

The perspective value can be set as none or a length measurement. The none value turns off any perspective, while the length value will set the depth of the perspective. The higher the value, the further away the perspective appears, thus creating a fairly low intensity perspective and a small three-dimensional change. The lower the value the closer the perspective appears, thus creating a high intensity perspective and a large three-dimensional change.

• Perspective Origin:

As with setting a transform-origin you can also set a perspective-origin. The same values used for the transform-origin property may also be used with the perspective-origin property, and maintain the same relationship to the element. The large difference between the two falls where the origin of a transform determines the coordinates used to calculate the change of a transform, while the origin of a perspective identifies the coordinates of the vanishing point of a transform.

3D Transforms:

Working with two-dimensional transforms we are able to alter elements on the horizontal and vertical axes, however there is another axis along which we can transform elements. Using three-dimensional transforms we can change elements on the z axis, giving us control of depth as well as length and width.

• 3D Rotate:

So far we’ve discussed how to rotate an object either clockwise or counterclockwise on a flat plane. With three-dimensional transforms we can rotate an element around any axes. To do so, we use three new transform values, including rotateX, rotateY, and rotateZ.

• 3D Scale:

By using the scaleZ three-dimensional transform elements may be scaled on the z axis. This isn’t extremely exciting when no other three-dimensional transforms are in place, as there is nothing in particular to scale. In the demonstration below the elements are being scaled up and down on the z axis, however the rotateX value is added in order to see the behavior of the scaleZ value. When removing the rotateX in this case, the elements will appear to be unchanged.

• 3D Translate:

Elements may also be translated on the z axis using the translateZ value. A negative value here will push an element further away on the z axis, resulting in a smaller element. Using a positive value will pull an element closer on the z axis, resulting in a larger element.

• 3D Skew:

Skew is the one two-dimensional transform that cannot be transformed on a three-dimensional scale. Elements may be skewed on the x and y axis, then transformed three-dimensionally as wished, but they cannot be skewed on the z axis.

• Shorthand 3D Transforms:

As with combining two-dimensional transforms, there are also properties to write out shorthand three-dimensional transforms. These properties include rotate3d, scale3d, transition3d, and matrix3d. These properties do require a bit more math, as well as a strong understanding of the matrices behind each transform. Should you be interested in looking a bit deeper into them, please do!.

Transform Style:

On occasion three-dimensional transforms will be applied on an element that is nested within a parent element which is also being transformed. In this event, the nested, transformed elements will not appear in their own three-dimensional space. To allow nested elements to transform in their own three-dimensional plane use the transform-style property with the preserve-3d value.

Backface Visibility:

When working with three-dimensional transforms, elements will occasionally be transformed in a way that causes them to face away from the screen. This may be caused by setting the rotateY(180deg) value for example. By default these elements are shown from the back. So if you prefer not to see these elements at all, set the backface-visibility property to hidden, and you will hide the element whenever it is facing away from the screen.

Transitions & Animations:

Transitions:

As mentioned, for a transition to take place, an element must have a change in state, and different styles must be identified for each state. The easiest way for determining styles for different states is by using the :hover, :focus, :active, and :target pseudo-classes.

There are four transition related properties in total, including transition-property, transition-duration, transition-timing-function, and transition-delay. Not all of these are required to build a transition, with the first three are the most popular.

• Transitional Property:

The transition-property property determines exactly what properties will be altered in conjunction with the other transitional properties. By default, all of the properties within an element’s different states will be altered upon change. However, only the properties identified within the transition-property value will be affected by any transitions.

• Transitional Properties:

It is important to note, not all properties may be transitioned, only properties that have an identifiable halfway point. Colors, font sizes, and the alike may be transitioned from one value to another as they have recognizable values in-between one another. The display property, for example, may not be transitioned as it does not have any midpoint.

• Transition Duration:

The duration in which a transition takes place is set using the transition-duration property. The value of this property can be set using general timing values, including seconds (s) and milliseconds (ms). These timing values may also come in fractional measurements, .2s for example.

• Transition Timing:

The transition-timing-function property is used to set the speed in which a transition will move. Knowing the duration from the transition-duration property a transition can have multiple speeds within a single duration. A few of the more popular keyword values for the transition-timing-function property include linear, ease-in, ease-out, and ease-in-out.

• Transition Delay:

On top of declaring the transition property, duration, and timing function, you can also set a delay with the transition-delay property. The delay sets a time value, seconds or milliseconds, that determines how long a transition should be stalled before executing. As with all other transition properties, to delay numerous transitions, each delay can be declared as comma separated values.

Shorthand Transitions:

Declaring every transition property individually can become quite intensive, especially with vendor prefixes. Fortunately there is a shorthand property, transition, capable of supporting all of these different properties and values. Using the transition value alone, you can set every transition value in the order of transition-property, transition-duration, transition-timing-function, and lastly transition-delay. Do not use commas with these values unless you are identifying numerous transitions.

Animations:

Transitions do a great job of building out visual interactions from one state to another, and are perfect for these kinds of single state changes. However, when more control is required, transitions need to have multiple states. In return, this is where animations pick up where transitions leave off.

• Animations Keyframes:

To set multiple points at which an element should undergo a transition, use the @keyframes rule. The @keyframes rule includes the animation name, any animation breakpoints, and the properties intended to be animated.

• Animation Name:

Once the keyframes for an animation have been declared they need to be assigned to an element. To do so, the animation-name property is used with the animation name, identified from the @keyframes rule, as the property value. The animation-name declaration is applied to the element in which the animation is to be applied to.

• Animation Duration, Timing Function, & Delay:

Once you have declared the animation-name property on an element, animations behave similarly to transitions. They include a duration, timing function, and delay if desired. To start, animations need a duration declared using the animation-duration property. As with transitions, the duration may be set in seconds or milliseconds.

Customizing Animations:

• Animation Iteration:

By default, animations run their cycle once from beginning to end and then stop. To have an animation repeat itself numerous times the animation-iteration-count property may be used. Values for the animation-iteration-count property include either an integer or the infinite keyword. Using an integer will repeat the animation as many times as specified, while the infinite keyword will repeat the animation indefinitely in a never ending fashion.

• Animation Direction:

On top of being able to set the number of times an animation repeats, you may also declare the direction an animation completes using the animation-direction property. Values for the animation-direction property include normal, reverse, alternate, and alternate-reverse.

• Animation Play State:

The animation-play-state property allows an animation to be played or paused using the running and paused keyword values respectively. When you play a paused animation, it will resume running from its current state rather than starting from the very beginning again.

• Animation Fill Mode:

The animation-fill-mode property identifies how an element should be styled either before, after, or before and after an animation is run. The animation-fill-mode property accepts four keyword values, including none, forwards, backwards, and both.