Vector Math¶
Vector Math functions are global methods that perform operations on arrays, treating them as mathematical vectors.
Unless otherwise specified, Vector Math methods are lenient about dimensions and return a value that is the dimension of the largest input Array object, filling in missing elements with zeros.
Unlike built-in JavaScript methods, such as Math.sin, these methods are not used with the Math prefix.
Example¶
This expression returns [11, 22, 3]:
add([10, 20], [1, 2, 3])
Methods¶
add()¶
add(vec1, vec2)
Description¶
Adds two vectors.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec1 |
Array | First vector to add. |
vec2 |
Array | Second vector to add. |
Returns¶
Array
clamp()¶
clamp(value, limit1, limit2)
Description¶
The value of each component of value is constrained to fall between the values of the corresponding values of limit1 and limit2.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
value |
Number or Array | Value to clamp. |
limit1 |
Number or Array | Minimum amount to clamp value to. |
limit2 |
Number or Array | Maximum amount to clamp value to. |
Returns¶
Number or Array
Example¶
Ensure that a wiggled amount never exceeds the 0-100 range:
const wiggled = wiggle(0.5, 500);
clamp(wiggled, 0, 500);
cross()¶
cross(vec1, vec2)
Description¶
Returns the vector cross product of vec1 and vec2.
Refer to a math reference or JavaScript guide for more information.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec1 |
Array (2- or 3-dimensional) | First vector to calculate cross product of. |
vec2 |
Array (2- or 3-dimensional) | Second vector to calculate cross product of. |
Returns¶
Array (2- or 3-dimensional)
div()¶
div(vec, amount)
Description¶
Divides every element of the vector by the amount.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec |
Array | The vector to divide |
amount |
Number | The amount to divide by |
Returns¶
Array
dot()¶
dot(vec1, vec2)
Description¶
Returns the dot (inner) product of the vector arguments.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec1 |
Array | First vector to calculate dot product of. |
vec2 |
Array | Second vector to calculate dot product of. |
Returns¶
Number
length()¶
length(vec[, point2])
Description¶
Returns the length of vector vec.
If a second argument is provided, instead treats the first argument as a point and returns the distance between the two points.
Tip
Using length() with two arguments is the same as length(sub(vec, point2)).
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec |
Array | The vector to normalize, or the first point to measure from. |
point2 |
Array | Optional. The second point to measure to. |
Returns¶
Number
Example¶
For example, add this expression to the Focus Distance property of a camera to lock the focal plane to the camera's point of interest so that the point of interest is in focus:
length(position, pointOfInterest)
lookAt()¶
lookAt(fromPoint, atPoint)
Description¶
Orients a layer to look at a given point, from a given point.
The return value can be used as an expression for the Orientation property, making the z-axis of the layer point at atPoint.
This method is especially useful for cameras and lights.
Tip
If you use this expression on a camera, turn off auto-orientation.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
fromPoint |
Array (3-dimensional) | The location (in world space) of the layer to orient. |
atPoint |
Array (3-dimensional) | The point (in world space) you want to point the layer at. |
Returns¶
Array (3-dimensional)
Example¶
This expression on the Orientation property of a spot light makes the light point at the anchor point of layer number 1 in the same composition:
lookAt(position, thisComp.layer(1).position)
mul()¶
mul(vec, amount)
Description¶
Multiplies every element of the vector by the amount.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec |
Array | The vector to multiply |
amount |
Number | The amount to multiply by |
Returns¶
Array
normalize()¶
normalize(vec)
Description¶
Normalizes the vector so that its length is 1.0.
Using the normalize method is a short way of performing the operation div(vec, length(vec)).
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec |
Array | The vector to normalize |
Returns¶
Array
sub()¶
sub(vec1, vec2)
Description¶
Subtracts two vectors.
Parameters¶
| Parameter | Type | Description |
|---|---|---|
vec1 |
Array | The first vector |
vec2 |
Array | The second vector |
Returns¶
Array