The hand tool is used to grab the ligand. In this mode, the ligand will follow the orientation and position of the player's hand in 3D space when the user activates the trigger button. Haptic feedback on the controllers is provided to give the player a feeling of weight and resistance, as well as a signal when ligand molecules are brushing against the protein's surface model. Players are also given the ability to freely rotate atoms along with their bonds by using the rotate tool, a method of interaction is directly inspired by molecular modeling kits. To perform this action, players must first grab an atom that they wish to act as an "anchor" with their offhand. Next, players use their primary hand to select an atom that determines their axis of rotation. This atom is referred to as the directional atom. An axis of rotation is defined from the vector pointing from the center of the anchor atom to the center of the directional atom. Several steps are required to calculate the angle of rotation. First, a perpendicular plane is formed using the vector between the two key atoms. Next, the position of the player's primary hand is then projected onto the plane. This point in space always lies upon the plane that is perpendicular to the axis of rotation. This new local space can be conceptualized as a 2D plane, where the (x,y) position of the two atoms are located precisely at (0,0). Every frame, an angle in degrees is calculated between the center of this space and the projected coordinate of the primary controller. The current angle is compared with that of the previous frame and a delta is calculated. The anchor atom is then rotated by this delta angle to produce a rotation that mimics the rotation of the hand around the axis of rotation. In addition, bonds between two atoms may be created or destroyed with the 'Make 'n Break' tool. This works very similarly to the rotate tool, by creating or destroying a bond once the user has selected two atoms.