The green molecule has to move from point A to point B. Blue area is an obstacle. The green molecule has one fixed point at the center of the circle and two moving parts with two degrees of freedom. The posible molecule conformations and moves are determened by two angles, φ1 (0, 2π) and φ2 (-π, π).
move the sliders to change the angles
In the configuration space the blue area is the obstacle, and the green circle is the molecule that has to move from A to B.
A free path from A to B exists, drag the molecule to see how it changes conformation as it moves though the workspace.