the video shows the robot walking a few steps while the body moves forward in a straight line.
All of the movements are generated by evaluating the model at the current time.
Basically: all feet are connected to eachother and to the center of the robot body by virtual springs. The robot center body is moved forward while the feet remain on the ground. The gaitgenerator runs the following cycle:
1. find the leg L that has the higest virtual force in the direction of movement (forwards)
2. check if L can be lifted without losing stability (i.e. toppling over)
3. if L can be lifted, move its foot upwards
4. generate the target for the foot based on the combined virtual spring forces and an extra virtual force in the movement direction
5. place the foot down at the generated position
This method of gaitgeneration is still far from finished. Next step is expanding the virtual spring model to provide an approximation of the kinematic limits of the robot.