No one has worked out a viable way for humans to shape change but researchers are working on ways to make objects look different to the way they really are.
One way is to use the same technology as to make an object invisible. Cover the front completely with a display and put cameras behind.
Supposed you want a truck to look like a car. The screen can show the car on the side of the truck. Round the edges it displays exactly what the cameras are showing behind the truck. The tank has disappeared and all that can be seen is a car!
Superhero powers: shape changing