Perspective-dependent Indirect Touch Input for 3D Polygon Extrusion

We present a two-handed indirect touch interaction technique for the extrusion of polygons within a 3D modeling tool that we have built for a horizontal/vertical dual touch screen setup. In particular, we introduce perspective-dependent touch gestures: using several graphical input areas on the horizontal display, the non-dominant hand navigates the virtual camera and thus continuously updates the spatial frame of reference within which the dominant hand performs extrusions with dragging gestures.