Tablet
Calibrate
Function
You can calibrate the tablet/digitizer
in one of two
ways: Known Reference Points
or Drawing Scale with New Reference
Points. Reference points are the foundations of whatever data
you
digitize into the computer. Takeoff bases everything from drawing
location to drawing scale on the reference points you digitize.
Drawing
Scale with New Reference Points method is very convenient when
you don't know the precise coordinates of the entities on your drawing.
As long as your can obtain the drawing scale from your plan, this
method can establish a coordinate system relative to the
position of the plan on the digitizer board. In addition to the
drawing scale, you are required to enter a random coordinate for
the first reference point, the default coordinate is (1000,1000).
Takeoff would computer the coordinate of
the second reference point that you pick based on the first point.
The coordinates of these two reference points would be saved and will
be display on the Tablet Calibration
Dialog next time when you calibrate the tablet, so you can
digitize back to the previous coordinates using Know Reference Points method if you
are working on the same drawing, though you might have moved or rotated
your drawing on the digitize board..
If you know the precise coordinates of
two points,
you can select Known
Reference Points method, which establishes a coordinate system
that is
exactly match the coordinates in the field or on your drawing.
Furthermore, Takeoff saves the coordinates of the two reference
points from previous calibration and displays them on the Tablet Calibration Dialog next time
when you calibrate the tablet. If you want to continue to work on
the same drawing, you can use the Know
Reference Points
method with the saved coordinates to digitize back to your previous
coordinates although you might have moved or rotated your
drawing on the digitizer board.
For accurate takeoff calculations, choose two points that can be easily
found in the field and are farther apart rather than closer together.
Prompts
Tablet
Calibration
Dialog
Specify the Calibration Methods. If you select Drawing Scale method,
enter the drawing scale and the coordinate of the first reference
point. Otherwise enter the exact coordinates of the first and second
reference points.
Pick first
reference point: pick a
point
on the drawing
Pick second
reference point: pick
another
point on the drawing
Keyboard Command: digsetup
Prerequisite: Have a
digitizer board and a puck connected to your computer, and have Wintab
driver installed. The digitizer has been correctly set up.