Figure 3.1 shows some of the buttons used by VMD. For example, the button in 3.1 A draws all the loaded files and the one in 3.1 C writes the current screen description for use in a ray-tracing program. Some buttons, as in 3.1 B, indicate if something is turned on or off by turning an indicator light on or off. They can be turned on or off by clicking on the button. Others, shown in 3.1 D, indicate that they are pressed by appearing recessed.
One common button usage motif in VMD is shown in figure 3.2. These indicate that the value in the middle can be increased by pressing the button(s) on the right and decreased by pressing the button(s) on the left. If there are two sets of buttons, as in 3.2 B, then the outer set of buttons change the number in larger increments than the inner set.
