Left mouse button is used for modeling operations. Its behavior changes according to the active tool, specified by the buttons below. Right mouse button is used for camera control. Right-mouse dragging on the model rotates the model. Right-mouse dragging on the background translates the model. Vertical right-mouse dragging near the right edge of the canvas changes zoom.
When the user draws a stroke on a blank canvas, the system generates
a new 3D model by inflating the closed area. The original stroke
appears as a blue control curve.
When the user draws an open stroke on the surface,
it becomes a new control curve (sorry this fails often).
When the user draws an open stroke accross the surface, it becomes a temporary
curve on the surface. If the user clicks somewhere, the temporary curve becomes
a new control curve. If the user draws a stroke on either side of the temporary
stroke, it cuts the model.
When the user draws a closed stroke on the surface,
it becomes a temporary curve on the surface.
If the user clicks somewhere, the temporary curve becomes a new control curve.
If the user draws a profile stroke, the system generates an extrusion.
If the user draws another closed loop on the opposite side of the surface, the system generates a tunnel.
Erase:
The user can erase parts of a control curve by dragging near the curve.
Change:
The user can change a blue control curve (smooth constraint) into a red control curve (sharp constraint), and vice versa.
Rub:
The user can smooth a curve by dragging back-and-forth near the curve.
