TPC lets you calibrate drawing objects to your survey.
Raster Image Example
Lets say you inserted a raster image (picture) that didn't have a corresponding world file. You've roughly sized and positioned it on your drawing, and now you want to scale, rotate and translate it to match.
•calibrate the picture to your survey using the Calibrate command
•select point pairs using locations on the picture that match control points in your survey
•TPC calibrates the picture to your survey and prompts you to create the associated world file
Calibrating a Photo (4:58) - Calibrate a background photo to your survey using both point pairs and point series
Calibrating an XRef
Let's say you want to XRef an existing CAD drawing to one of your TPC drawings
•insert the XRef to that drawing into your TPC Drawing
•calibrate that XRef to your survey using the Calibrate command
•select point pairs using common points found in both your existing survey or drawing and the inserted XRef
•TPC calibrates the XRef so that it now matches your survey
•if the the XRef CAD drawing is updated in the future, those changes will automatically be calibrated when the XRef displays itself in the TPC drawing
Saving a Calibration
If you are likely to repeat what you did sometime in the future, you should save the calibration after you create it. Now, the next time you import data from that source, you can simply re-use that calibration.
If you do not save a drawing calibration, the drawing objects can not be Uncalibrated. The calibration can however, be reversed with the Drawing View's Undo command.
Exporting Data Back Out
The other advantage of saving the calibration you create for drawing data is that you can use the same calibration to export data back to the other coordinate system.
In the first example above, where you imported a DWG file, exporting your data back out to a new DWG file, using the same calibration, but in reverse, would result in that exported data being in the local grid (UCS) of the original DWG file.
Ad-hoc Calibrations
When calibrating drawing objects, you may not want to save the calibration. An example is when calibrating a photo to your survey. TPC creates the world file for the calibrated photo, so there is no need to save the calibration. Calibrating photos is also not very exact, as points are selected on the image that match survey points and their selection may be subjective. TPC calls these ad-hoc calibrations. TPC performs the calibration, but does not store the calibration for reuse or future reference.
Calibrating Tools in the Drawing Data Manager
Sometimes you will want to use the Drawing Data Manager to calibrate and Uncalibrate both survey and drawing data. The Drawing Data Manager has calibration tools to do this.
