02-08-2007, 02:08 PM
Um, if you open a .pdf document, you get the Adobe Acrobat Reader (or full-blown Acrobat, or other application). AAR displays the document with an 'open hand' icon showing. When you click the 'hand' clenches and mouse/cursor movement drags the document. When you release the click, the hand unclenches and dragging stops.
The motion of the cursor is directly tied to postion of/over the document.
QTVR used a speed control based on distance from the center of the viewing window. The further, the faster. Direction of motion also determined by radial displacement from the center.
Rate-of-motion is hard to control well for the casual user (like me).
It does not require as much physical movement as absolute-postion (click-and-drag), but is not forgiving of positioning error.
Second-order systems, where the controls only adjust the rate-of-change (flight control simulators) are even harder to deal with. I don't fly. There is a reason for it. Be thankful!
The motion of the cursor is directly tied to postion of/over the document.
QTVR used a speed control based on distance from the center of the viewing window. The further, the faster. Direction of motion also determined by radial displacement from the center.
Rate-of-motion is hard to control well for the casual user (like me).
It does not require as much physical movement as absolute-postion (click-and-drag), but is not forgiving of positioning error.
Second-order systems, where the controls only adjust the rate-of-change (flight control simulators) are even harder to deal with. I don't fly. There is a reason for it. Be thankful!