To add,
Resolume is already extremely close to being able to do this. You can change the crop size of a slice in the "Input Selection" tab in Advanced Screen Setup, and then skew the slice in the "Output Transform" tab.
The only difference is that you can't adjust the position of a specific point of your slice while in the Input Selection. It forces you to move at least two points on either the Y or X axis.
Being able to move a specific point, while also being able to add more points (similar to double clicking a crop to add a point) would be extremely useful and avoid the use of any 3rd party software for aligning custom animations to stages.
Please add this feature in the next update!!