A Collection of Expressions for Adobe After Effects

This is a minor collection containing very useful 21 expressions for Adobe After Effects. This was released from Total Training Adobe After Effects Professional Learning pack.rnrnEnJoY!rnrnCIRCLE FUNrnThis generates perfect circular motion centered around the original position of the layer. I recommend that you map the radius and cycle inputs to Expression Control sliders, and the phase input to an Expression Control angle. This generates perfect circular motion centered around the original position of the layer. I recommend that you map the radius and cycle inputs to Expression Control sliders, and the phase input to an Expression Control angle.rnrnTRACK A CHILDrnThis expression is designed to track the position of a layer that has been parented to one or more layers. Use the expression below on the position property that you wish to animate, changing the name "Child" to match the name of the layer you wish to track. For instance, if you want to use write-on to track the position of a layer called "moon", apply this expression to the "brush position" property of the write-on filter, and change "child" to "moon".rnrnADJUSTABLE WIGGLErnUse this expression as an interactive, keyframeable Wiggler. Apply it to the property of the layer you wish to wiggle. The variable names in the first three lines can be named whatever you like, but remember to change their corresponding use in the last line of the script.rnrnONE-DIMENSIONAL POSITION WIGGLErnUse this expression as an interactive, keyframeable Wiggler, but constrained along a single axis. Apply it to the position or anchor point of the layer you wish to wiggle.rnrnOSCILLATE POSITIONrnCreates an oscillating motion between two specified 2-dimensional positions over a specified period of time (in seconds). Use an adjustment layer with Expression Control position points for " from", "to", and an Expression Control slider assigned to "period". Change "linear" to "ease" for smoother interpolation.rnrnOSCILLATE ROTATIONrn{ OR ANY SINGLE VALUE }rnCreates an oscillating motion between two specified values over a specified period of time (in seconds). Use Expression Control angles or sliders for "from", "to", and an Expression Control slider assigned to "period" for fine control. You can apply these to any layer. Change "linear"; to "ease" for smoother interpolation.rnrnBOUNCErnCreates a bouncing (sine wave) motion between two specified 2 dimensional positions over a specified period of time (in seconds). Useful for creating bouncing balls. Use Expression Control position points for "from", "to", and an Expression Control slider assigned to "period" for fine control. You can apply these to any layer.rnrnWIGGLE FROM LEADERrnThese two expressions create a " follow the leader" effect. One works from the top down, the other from the bottom up. Only use one. A follower will tag along after the leader, deviating from the path according to the wiggle properties that are specified in the inputs. Once appliedrnto a single follower, you can duplicate the layer as many times as you like and each subsequent copy will follow along, offset in time from the last and wiggling uniquely. In this expression, the wiggle is based on the position of the leader. Link Expression control sliders to lag (to interactively control how bunched together the layers are), wigfreq (to control the frequency of the wiggle) and wigamp (to control the amplitude of the wiggle). Apply Expression control effects to the leader only.rnChange the word "Leader" to match the name of the leading layer.rnrnWIGGLE FROM PREVIOUSrnThis creates a "follow the leader" effect that works from the bottom up. A follower will tag along after the previous layer, deviating from the previous path according to the wiggle properties that are specified in the inputs. Once applied to a single follower, you can duplicate the layer as many times as you like and each subsequent copy will follow along, offset from the last in time and wiggling uniquely. In this expression, the wiggle is based on the position of the previous layer.rnLink Expression Control sliders to lag (to interactively control how bunched together the layers are), wigfreq (to control the frequency of the wiggle) and wigamp (to control the amplitude of the wiggle). Apply Expression Control effects to the leader only. Change the word "Leader" to match the name of the leading layer.rnrn2D LOOK ATrnApply this Expression to the Rotation channel of any layer you wish to control. Set LookAt, below, to the name of the layer you wish the layer to look at. If the controlled layer is not initially pointing straight up, enter an offset amount in degrees, below, to adjust the direction it is looking.rnrn3D LOOK ATrnApply this expression to the orientation channel of the layer you wish to have look at another layer (the layer being controlled). Enter the name of the layer to look at in LookAt below. If the layer being controlled does not correctly look at other layer, adjust the layer offset by changing the X, Y and Z rotation values (not the orientation values) for the layer beingrncontrolled.rnrnANGLE OF VIEW ZOOMERrnThis allows you to control the angle of view of a camera interactively, by scaling a null object on screen. To use: Create a null called "angle_zoomer". Animate the null\'s scale to control viewing angle in degrees.rnrnFOCAL LENGTH ZOOMERrnThis expression will allow you to zoom a camera in After Effects using real-world focal length values. To use this expression:rn1. Create a camera.rn2. Create a null layer called "focal_zoomer" and turn off its visibility switch in the timeline.rn3. Apply the expression below to the Zoom parameter of the camera.rn4. Set the value of hFilmPlane in the expression to the size of your film, in millimeters.rn5. Animate the null\'s scale to control the focal length of the camera, in millimeters.rnrnCAMERA AUTOFOCUSrnApply this expression to the Focus Distance of your camera, then change the name "Focus Layer" below, to the name of the layer you wish to keep in focus.rnrnCONNECTORrnThese Expressions can be used to make a connector that stretches like a rubber band between two layers, which by default are named "End 1" and "End 2". Obviously you can change these names to anything you like. The connector layer wants to be a horizontal rectangle, with the anchor point of the layer moved to the left center edge of the layer.rnThe connector has 3 separate expressions applied to it: one for position, one for rotation and one for scale. rnrnGEARSrnThis Expression causes one gear to rotate at the proper speed when a second gear next to it is rotated, so that the two gears stay meshed with each other. To use this expression, first create and import two gears that mesh together properly. In order for two gears to mesh properly, the ratio of the difference in size between the two gears must equal the ratio of the difference in the number of teeth between the two gears. Once imported, decide which gear will be the Leader and which will be the Follower. Apply the Expression below to the Rotation parameter of the Follower gear. Then set the LayerToFollow, in the Expression, to the name of the Leader gear. Set the Ratio in the expression to the size of the Leader, relative to the Follower.rnrnPATH TEXT LEVELERrnThis Expression will automatically keep the text in Path Text level within the comp. Useful for when you simply want to make a straight line or paragraph of text in Path Text, without taking it follow a path. It allows you to use the extra kerning, spacing and other features of Path Text with ordinary straight text. rnrnTEMPORARY PARENTINGrnUsing the analogy of an eagle picking up a fish and dropping it in a nest, these two expressions can be used to parent one layer to another for only a portion of a longer animation.rnrnTRACK EFFECT PARAMETERrnThis expression will track any effect point on a layer, regardless of size, position, or scale of the layer, and translate it to positional values that are relative to the comp. For example, For example, you could have a small layer with corner pin applied, and use this expression to track another layer to the lower right corner of the effect, regardless of how the layer is moved. This expression will not take into account the scale or rotation of the source layer.rnrnDECAYING BOUNCErnThis expression allows you to "drop" a layer from the top of the screen and have it bounce in the center of the comp as if tied to a string, with a bounce decay control. First, create a small solid called "Control Layer" and hide it in the timeline. Add 3 Slider Control effects, naming them "velo control", "amplitude control" and "decay control". Suggested initial slider values for each are -200, -200 and 4 respectively. Paste the expression below into the Position property of the layer you wish to bounce, and be sure to set the layer\'s anchor point to the correct location, such as the bottom edge if dropping from the top.rnrnSQUISHY SQUASHYrnThis expression allows you to "drop"; a layer from any position (defined by your own position keyframes) and have it bounce in the center of the comp as if tied to a string, with a bounce decay control. First, create a small solid called "squash control" and hide it in the timeline. Add 3 Slider Control effects, naming them "maxDev control", "spd control" and "decay control". Suggested initial slider value for decay control is 2.