Creating a Transition with Masking

[enzof38289110]

I'm new to masking and need some advice on the best way to do approach a transition in After Effects. I've included a storyboard image on what I want to do. I want the mask to expand horizontally first and then vertically.

[Mike_Abbott]

1. Select all the 'green' text layers and green background. Layer > Precompose.
2. With that precomp layer selected, double click the rectangle tool icon in the toolbox. This will make a mask that fits your layer - and is therefore centred on the comp.
3. Hit Ctrl (Cmd) T. This will activate a free transform box for your mask.
4. Ctl (Cmd) drag the top handle to reduce the height of the mask to encompass your 'CRAZY GOOD' text, while keeping it central.
5. Twirl down Masks > Mask 1 and set a keyframe for Mask path for this mask at the appropriate time.
6. Drag playhead to start position. Hit Ctrl (Cmd) T. Ctrl (Cmd) drag a side handle to reduce the width of the mask to nothing.
7. Drag playhead to end position. Hit Ctrl (Cmd) T. Ctrl (Cmd) drag the top handle to increase the height of the mask to encompass the other text above and below.