Tablet Calibrate
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.
![Calibrate-Reference Points](cal2.bmp)
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.