The Triangular Script:
One click triangles for After Effects

How the Triangular script works

Creating a triangle in After Effects is surprisingly long winded: first you have to click+hold the shape tool to bring up the polygon option, then when you click and drag your shape you have to press down on the keyboard to reduce the number of points until you create a triangle.

With the Triangular script: All you have to do is select the layer you want to add a triangle mask to, and hit the button!

Alternatively, if you want to create a triangle shape layer, just make sure no layers are selected and hit the button.

Centred Rotation

There's also another feature of the triangular script that comes in useful if you want to rotate a triangle mask layer evenly without wobble.

Holding the Ctrl key when you're adding a triangle mask will centre the layer's anchor point to the centre of the triangle, rather than the centre of the layer. This means when you rotate the layer, it will rotate the triangle without being off balance.