Understanding digitizer tablet transformation types

Depending on the number of points specified, you have a choice of transformation types to use, along with the type recommended for IntelliCAD.

Transformation refers to the calculation of the points on the screen that correspond to points you digitize on the tablet.

Number of points specified Transformational type recommended "Best fit" (approximate)
2 Orthogonal None
3 Affine Orthogonal
4 Projective Orthogonal, Affline
5-10 None Orthogonal, Affline

Choose the recommended type unless you know it will not be appropriate for what you are digitizing. The most appropriate type is not always the one with the least error; for example, you might digitize three points and select the orthogonal transformation, even though the affine transformation would yield a closer representation of your calibration entries.

 

 

Digitizing by selecting points (1, 2, 3, and 4) on the tablet.

Corresponding screen coordinates:
1 Coordinate specification X0, Y0, Z0
2 Coordinate specification X0, Y5, Z0
3 Coordinate specification X5, Y5, Z0
4 Coordinate specification X5, Y0, Z0

 

 

 

Screen result of orthogonal transformation after tracing polyline on tablet.

Screen result of affine transformation after tracing polyline on tablet.

Screen result of projective transformation after tracing polyline on tablet.

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Calibrating the digitizer tablet

Configuring digitizer tablet

Using a digitizer tablet

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Calibrate your tablet for digitizing points

Configure the tablet for menu input

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