In this exercise we will make a self-propelled car with no steering – we will make a steerable, self-propelled car in a later exercise. Don’t forget to save often whenever you work with SketchyPhysics – it is not as stable as most programs. In fact it would even be a good idea to make backup copies as you go – save ‘car_a’ and then two minutes later use ‘save as to save ‘car_b’ etc so that even if SketchyPhysics crashes you will not lose too much. The problem is that if you save a version that crashes when you then run it then each time you open that invalid saved file it will always crash when you run it – it may be irreparable.
The finished vehicle:
You should have saved you work several times already. Save your work again now and any time you are about to press the Play button and run your animation for this is the moment SketchyPhysics is most likely to crash. Then press the play button in the ‘Sketchy Physics’ toolbar. The car should drop down onto the solid floor and then propel itself forwards. You can pull the car around with the mouse to stop it falling off the floor.
To stop and reset the animation, press the reset button.
Worth trying: While the animation is running, right-click the vehicle and choose ‘camera track’ to make the camera rotate (and ONLY rotate) to follow the motion of the vehicle so the vehicle never goes out of the window. If you choose ‘camera follow’ then the camera does not rotate, it actually MOVES to keep a constant position compared to the vehicle. If you choose ‘camera clear’ then the camera is reset so that it no longer moves or rotates during the animation.
Note that in this exercise we used a ‘hinge’ as a motor rather than using the ‘motor’ joint.