Digitizing Tablet

Command: TABLET

The Tablet command configures and calibrates a digitizing tablet and toggles tablet mode.

This command requires that Wintab32.dll from Wacom Technology, Corp. be installed on the computer. Download Wintab32.dll from the internet, then place the file in your system directory: C:\Windows\System32.

A digitizing tablet, also called a graphics tablet, a graphics pad or drawing tablet, is a computer input device that allows you to hand-draw images and graphics, similar to the way one draws images with a pencil and paper. In a CAD program a digitizing  tablet can be used to trace paper drawings into a drawing file or to launch drawing commands from a digitizing tablet overlay.

To use a digitizing tablet in BricsCAD

In order to prepare BricsCAD for using a digitizing tablet do the following:

• Install the appropriate driver for your tablet.

• Make sure Wintab32.dll exists in C:\Windows\System32.

• Download the tablet overlay and CUI files.

• Print the BricsCAD tablet overlay.

• Load the overlay CUI file.

• Start BricsCAD, then initialize the tablet.

• Configure the tablet: part of the tablet surface is used as the menu area, another part as the screen pointing area.

• Calibrate the tablet: a calibrated tablet can be used to trace the geometry of a paper drawing or image into a drawing.

To download the tablet overlay and CUI files

1. Go to the BricsCAD Documentation and Tools page on the Bricsys website.

2. Scroll down to the bottom of the page and click the DOWNLOAD button under Tablet overlay.

2. Save the tablet.zip file.

The zip-file contains the following files:

• overlay.png: an image of the tablet overlay
• overlay(A3).pdf: to print the tablet overlay on a A3 paper size.
• overlay(cm).dwg: a DWG in which the overlay.png is attached as an image.
  The drawing contains two layouts to print the overlay using decimal units.
• overlay(inch).dwg: a DWG in which the overlay.png is attached as an image.
  The drawing contains two layouts to print the overlay using imperial units.
• tablet.cui: a partial cui file to be used with a tablet.
• tablet(acadLike).cui: an AutoCAD-like partial cui file to be used with a tablet.

Please make sure the overlay.png image file is extracted to the same folder as the DWG's.

To load the overlay CUI file

1. Extract the overlay CUI files to the Support folder of the roamable root folder (see BricsCAD User Files).
   E.g. C:\Documents and Settings\<user name>\Application Data\Bricsys\BricsCAD\V...\en_US\Support on Windows XP;
   C:\Users\<user name>\AppData\Roaming\Bricsys\BricsCAD\V...\en_US\Support on Windows Vista and Windows 7.
2. Load Tablet.cui as a partial CUI (see To load a partial CUI file).
   The next time you start BricsCAD, Tablet.cui will be loaded automatically.

To switch the tablet ON / OFF

Do one of the following:

• Click the TABLET field in the Status Bar.
• Press the F4 function key to toggle the tablet mode.
• Choose Tablet On or Tablet Off in the Settings menu.
• Type tablet in the command bar, press Enter,  then type ON or OFF ;
  or
  click ON or OFF in the prompt box.

To configure the tablet

1. Do one of the following:
2. Choose Tablet  in the Settings menu, then choose Configure... in the flyout menu.
   
   +
3. Type tablet in the command bar and press Enter.
   The command bar reads: Tablet: ON/OFF/CALibrate/ConFiGure/<On>:
   a prompt menu displays:
   
   
   Type cfg in the command bar and press Enter or choose Configure in the prompt menu.

The command bar reads: Do you want to align the tablet overlay? Yes/No/<No>:

2. Type Y in the command bar and press Enter or choose Yes in the prompt menu.
   The command bar reads: Digitize upper left corner of the overlay:
3. Click on the mark in the upper left corner (1) of the digitizing tablet overlay.
   
   
   
   The command bar reads: Digitize the lower left corner of the overlay.
4. Click on the mark in the lower left corner (2)  of the digitizing tablet overlay.
   The command bar reads: Digitize the lower right corner of the overlay.
5. Click on the mark in the lower right corner (3)  of the digitizing tablet overlay.
   The command bar reads: Digitize the lower left corner of the screen pointing area:
6. Click on the mark at position (4) on the of the digitizing tablet overlay.
   The command bar reads: Digitize the upper right corner of the screen pointing area:
7. Click on the mark at position (5) on the of the digitizing tablet overlay.
   The command bar reads: Tablet configured.

To calibrate the tablet

To calibrate the digitizing tablet you must specify at least two points. The more additional points you specify, the more accurate the digitizing process. Additional points are particularly recommended when digitizing a non-orthogonal image, such as an aerial photograph.

1. Do one of the following:
2. Choose Tablet  in the Settings menu, then choose Calibrate... in the flyout menu.
   
   +
3. Type tablet in the command bar and press Enter.
   The command bar reads: Tablet: ON/OFF/CALibrate/ConFiGure/<On>:
   a prompt menu displays:
   
   
   Type cal in the command bar and press Enter or choose Calibrate in the prompt menu.

The command bar reads: Digitize point #1:

2. Click a point on the digitizing tablet .
   The command bar reads: Enter coordinates for point #1:
3. Do one of the following:
4. Click a point in the BricsCAD drawing window.
5. Enter the coordinates (x,y) in the command bar.

The command bar reads: Digitize point #2:

4. Repeat step 3 to specify the following calibration point.
   The command bar reads: Digitize point #3 (or ENTER to end):
5. Do one of the following:
6. Repeat step 4 to specify an additional calibration point.
   (You can  specify up to 10 calibration points).
7. Press Enter to conclude the calibration process.
   The command bar reads:
   if 2 calibration points are specified: Tablet calibrated.
   if 3 or more than 4 calibration points are specified: Select transformation type Orthogonal/Affine:
   if 4 calibration points are specified: Select transformation type Orthogonal/Affine/Projective:

6. Select the transformation type.
   Transformation refers to the calculation of the points on the screen that correspond to points you digitize on the tablet.

Orthogonal (left): To be used with accurate paper drawings. Orthogonal transformation maintains all angles and preserves relative distances. If only two calibration points are specified orthogonal transformation is generated automatically.

Affine (middle): Maintains parallel lines, but not necessarily the angles between intersecting lines.

Projective (right): Does not maintain parallel lines, nor angles.