| 摘要 |
PURPOSE:To form a perspective drawing while displaying a straight line passing a focus by displaying a straight line connecting the focus on which a straight line passing a visual point after specification and parallel with the axis of an affine coordinate system intersects with a part of a screen face to a cursor existing in a window. CONSTITUTION:A computer 1 executes operation, storage and I/O processing, a CRT 2 displays a graphic window 5, a command menu 6, etc., and function keys F1 to F7 are used for inputting a specific command for forming a perspective drawing. While observing the CRT 2, relation among an optional three- dimensional affine coordinate system, the screen face and a visual point is specified through the computer 1 by operating a keyboard 3 and a mouse 4 and a straight line connecting a focus on which a straight line passing a visual point after the specification and parallel with the axis of the affine coordinate system intersects with the screen face to the cursor existing in the window 5 for displaying a part of the screen face is displayed. Thus a perspective drawing can be formed while displaying the straight line passing the focus. |
