interactive Gives tools to interact with the rendered area. When one wants some interactions on the rendering area (either from the mouse or from the keyboard), one should initialise it using openGLInteractiveInit_session(). Then, during the interactive session, several modes have been implemented: openGLInteractiveBegin_mark(), is a mode where the mouse can select a node and this nodes become highlighted. openGLInteractiveBegin_move(), the mouse is then used to move picked nodes. Moves are possible in the plane of the screen or constrained along axis of the bounding box. openGLInteractiveBegin_observe(), in this mode, the mouse is used to change the position of camera, its orientation and its zoom characteristics. openGLInteractiveBegin_pick(), this mode is the most complex picking mode. It can select atoms up to two references and measure distances and angles. openGLInteractiveBegin_pickAndObserve(), this mode is a simplified mix of obervation and picking. The observe mode has two different moving algorithms that can be changed using openGLInteractiveSet_preferedObserveMethod(). The first, called 'constrained' (cf. #OPENGL_OBSERVE_CONSTRAINED) corresponds to movements along parallels and meridians. When the mouse is moved along x axis, the camera raotates along a parallel. When the camera is moved along y axis, the camera rotate along a meridian. The top is always pointing to the north pole (in fact, omega is always forced to 0 in this mode). This mode has a 'strange' behavior when the observer is near a pole: moving mouse along x axis make the box rotates on itself. It is normal, because movements on x axis is equivalent to movements on parallel and near the poles, parallel are small circle around the z axis. This can be unnatural in some occasion and the other mode, called 'walker' (see #OPENGL_OBSERVE_WALKER) can be used instead of the 'constrained' mode. In the former, the moving is done has if the observer was a walking ant on a sphere : moving the mouse along y axis makes the ant go on or forward ; and x axis movements makes the ant goes on its left or on it right. This is a more natural way to move the box but it has the inconvient that it is hard to return in a given position (omega has never the right value). @data: @node: @button: @shiftMod: @x: @y: @pickData: @data: @window: @handler: @data: @stopPickObserve: @data: @method: @Returns: @data: @Returns: