In this transition one shot replaces another by traveling from one side of the frame to another or with a special shape.
If the transition is to use a shape then this is chosen with theoption.
You can install new wipe files from Download New Wipes on the .
There was a defect with the download new wipe files - it did not download them to where they are needed. They should go here ~/.local/share/kdenlive/lumas/HD/
but were going here ~/.local/share/kdenlive/lumas/
To fix manually create a HD folder and move the .pgm files there
This defect does not appear in version 17.12.3
This clip has some examples of the different wipes Kdenlive is capable of.
See also Composite Transition