### effect

One of the following:

```
barn door open
barn door close
checkerboard
dissolve
iris open
iris close
plain
push down
push up
push left
push right
scroll down
scroll up
scroll left
scroll right
shrink to top
shrink to center
shrink to bottom
stretch from top
stretch from center
stretch from bottom
venetian blinds
wipe up
wipe down
wipe left
wipe right
zoom close
zoom in
zoom open
zoom out
```