Take video shots of real people moving around in a setup as to the left. Build up in difficulty: 2 people not colliding, 2 people colliding, both with and without 1 or 2 people standing still. Also in the dimension of ease of separating the people from the floor.
It is advisable to organise a joint session for this, e.g. on 19 april. There is enough open space in the building to find a suitable location. You need a webcam connected to a laptop, a digital camera might be an alternative. Be sure that you can make a video such that you can access the individual images, and store them as individual files: img000.ppm, img001.ppm,...,img199.ppm. In quickcaminf.zip you find an example to read out a quickcam and set the various parameters of the camera.
Make also some measurements to find the Z=f(y) for each video shot.