3D Measurements

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Interactive 3D Measurement Tool

One of the great strengths of the PCB editor is that it allows you to design in 3D. The loaded board can viewed, rotated and examined in detail, and clearance violations displayed and resolved.

3D clearance checking is great for detecting collisions, but another important aspect of design is ensuring that the clearances that are there, are correct. Are those buttons the right distance apart? what's the clearance between that surface of the connector and the case? just how much room is there under that display? - these are typical questions a designer will ask themselves every day.

The new 3D measurement feature will you help answer these questions.

As well as measuring from one object to another, you can also hold the Ctrl key to select a specific face on an object. As you hold Ctrl the face under the cursor will highlight.

Performing a 3D Measurement

To use the tool, run the Reports » Measure 3D Objects command and keep an eye on the Status bar:

  • You will be prompted to Choose First 3D Object or Face.
  • As you move the cursor over a potential 3D object, the color of that object will change to green.
  • If you are holding Ctrl, the face under the cursor will highlight (more on this below).

After you click the first object, the tool will report the:

  • Shortest distance from underside of the chosen object (face) to the board surface
  • Shortest distance from the chosen object (face) to the board edge

You will then be prompted to Choose Second 3D Object or Face. After you click on the second object (face), the tool will again report the board surface and edge distances for the second object, and this time will also report the:

  • Shortest distance between the 2 chosen objects (faces).
  • The 3D Distance dialog will open, displaying the measurement results. When you have finished examining the results in the 3D Distance dialog, click the OK button to close the dialog.

You remain in 3D Measurement mode, ready to perform the next measurement.

  • Press Q to toggle the units,
  • Press Shift+C to clear the current measurements, then take the next measurement, or
  • Press Esc or right-mouse click to drop out of 3D measurement mode.

Measure the distance between two 3D objects, press Q to toggle between metric and imperial, press Shift+C to clear the results.

All measurement results are logged in the Message panel, you can double-click on a previous entry to cross probe to that measurement.

Cross-Probing from the Results

3D measurement is also an interactive tool - as well as displaying the results in the 3D Distance dialog - they are also logged to the the Messages panel. After you have dropped out of 3D Measurement mode you can double click on an entry in the Messages panel to jump to that measurement result again.

As well as displaying the distance between the 2 chosen objects, other useful measurements are displayed in the Messages panel - double-click to cross probe.

After completing your first measurement you remain in measurement mode, ready to take another measurement. Right-click when you have finished taking measurements, then double-click on an entry in the Messages panel to cross probe to that result. Note that you will not jump to a result where the value is zero - because these are not marked there is no specific location for the software to jump to.

The information about the chosen 3D Object includes the Identifier of the chosen 3D Body objects (in parentheses). Having a value for the Identifier will help you know that you have clicked on the right object.

Face-to-Face Measurements

An essential feature of the tool is the ability to select a specific face on the 3D Object - hold Ctrl during object selection to identify the required face.

Hold Ctrl to select a specific face in the 3D Body object, in the image on the left the barrels of the RCA connector are being selected. The result is shown in the right image.

To help identify the face of interest, the following highlighting techniques are used:

  • If the 3D Object under the cursor is a STEP model, then the entire model will be displayed as transparent, except for the face under the cursor. This face will also be outlined in blue.
  • If the 3D Object under the cursor is an Altium Designer generic 3D Body Object, then the face under the cursor will be outlined in blue.

During the measurement process, you can press Shift+C to clear the display of measurements.

Interpreting the Measurement Results

The measurement tool performs three sets of measurements:

  • from the first object to the board,
  • from the second object to the board, and
  • between the two objects.

The tool calculates the distance between the two closest points on the chosen objects (or faces) - this distance is displayed in yellow. All other measurements are shown in light blue.

Object-to-Object Measurement

In the image below, the shortest distance between the chosen objects is 4.049mm. The X, Y, Z triangulation lines used to calculate this distance, and their measurements, are shown in light blue.

In this image, the first object chosen was the upper end cap on the surface mount capacitor on the left (the model was created from three, 3D Body objects), and the second object was the underside of the right-angle leg of a voltage regulator, on the right. The closest points of these objects has been highlighted with a purple arrow - it is between these two points that the measurement has been performed.

The software calculate the shortest distance between the two chosen objects, and displays this value in yellow. For this image the object-to-board measurements have been removed.

Object-to-Board Measurements

To calculate the object-to-object distance, the tool must first calculate the location of each of the selected objects. The results of these object-location measurements are also displayed. For the object-to-board measurements, the software calculates the distance from:

  • the reference point on the object, to the board surface (Z measurement), and
  • the reference point on the object, to the board edge (X or Y measurement).

As with the object-to-object measurement, it also triangulates from the reference point on the object to the reference point on the board, and displays this direct distance in yellow.

To help spread out the amount of data being displayed, if the edge of the reference object is parallel to the board edge, then the object-to-board measurements are displayed on one corner of that edge, and the object-to-board edge measurements are displayed on the other corner of that edge, as can be seen in the image below. Hover to see the objects before the measurement was taken.

An example of the object-to-board edge measurements, from the underside of a plug-in module down to the main board. Note the measurement at the far end, this is the object-to-board measurement.
Hover to see the board before the measurement was performed.

Enhanced 2D Measurement Tool

The 2D Measurement tool has also been improved. It also reports each measurement in the Messages panel while remaining in measurement mode, ready to take your next measurement. Right-click when you have finished measuring, double-click on a result in the Messages panel to cross-probe to that measurement and display it's X distance, Y distance and direct XY distance.

Double-click on a result in the Messages panel to cross-probe to, and display, a 2D measurement result.

Press Shift+C or click the  button to clear the measurement lines.

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