Since Smode 8.4, every VideoProjector have now their own 3D space, which allows you to transform in placement and warp, every GroupStageElement that are taken into account by your video projector.
Click on "EDIT SOURCE" recreate the current perspective. Maintain CTRL and click to create new points. You are also able to create segment between points. Remove te points or segement by maintaining SHIFT and click.
Then, modify the position of your points thanks the "EDIT TARGET" button
Once your mapping is ready, and for more safety, lock your warping thank the "LOCK" button
The example below show you how it works: