The Measure Tool is used to take various types of measurements of one or more scene objects.
The hotkey for the Measure tool is m.
The property panel for Measure is shown to the right. The Type and Direction flyouts are used to select the type of measurement you wish to take.
The Snapping Mode drop-down allows you to enable a few basic snapping options, to take more precise measurements. The q hotkey cycles through these options. Note that the Measure tool will also snap to visible Pivots in the scene. There are more snapping modes in the Create Pivot tool, so in some cases it may be necessary to use Pivots to take precise measurements.
There are a variety of quite different measurement types available in the Type flyout shown below. There are two main categories. In the top row, the measurement is taken from a single point - the measure point - in a fixed direction, to various distances. The default direction is the surface normal, unless the Direction flyout is modified.
In the top row, from left-to-right we have:
Local Thickness: distance from measure point to first ray-hit location, ray through object
Local Clearance: distance from measure point to first ray-hit location, ray away from object
Total Thickness: distance from measure point to furthest ray-hit location, ray through object
Max Distance: distance from measure point to furthest ray-hit location, ray away from object
The second row contains three other types, from left-to-right:
Point-to-Point: distance between two measure points
Point Coordinates: X/Y/Z coordinates of measure point
Fit Cylinder: radius of cylinder fit to a set of accumulated measure points
The image below shows two sample usages of the basic top-row measure types. To set the measure point you left-click on the surface of the model. As soon as you press down the mouse button, the measurement value will appear on the right edge of the 3D view, as shown in the image below-left. The measurement distance is shown in 3D, as a red line, however in this image is is quite small.
If you continue to hold the left button and move the mouse, the measurements will be accumulated, as shown above-right. This is why three numbers are shown on the right. The middle black number shows the measurement at the cursor point. The upper grey number is the maximum measured value along the mouse path, and the lower grey number is the minimum measured value. The purpose of these is so that you can scrub over an area to find the min and max values, which may be useful if you are trying to verify a tolerance or determine a maximum thickness, for example.
This measure type is similar to the single-point modes, but you explicitly define both the start and end of the measurement, instead of using a raycast. The second point is positioned by either shift-left-click or right-click if available. Like the single-point modes, the values to the right show the minimum and maximum distances over a single click-drag movement.
This measure type allows you to query the 3D position of a point on the model surface. Instead of a single measurement value, the three X/Y/Z coordinates are shown to the right. The measurement point is shown as a small red dot.
The Cylinder measure type is used to find a best-fit cylinder for a set of points. This is useful to estimate radial dimensions. However, we do note that the Fit Primitive Tool now can also do a similar cylinder fitting, in what we feel is a simpler workflow. So, we recommend using that and then measuring the resulting cylinder. However, if you really want to use Cylinder mode, the way it works is that you draw sample points by left-click-dragging. As soon as enough are available, a semi-transparent blue cylinder will be fit. The middle measurement to the right is the radius of the current cylinder. You can rotate the view and draw additional sample points, to improve the fitting. To reset the cylinder, you must change the measurement type.
The Direction flyout is used to change the ray direction used in the single-point modes described above. The default is the normal direction. You can instead use the canonical world-space X, Y, and Z axis directions, by selecting the appropriate button in the flyout. These can be useful in different situations, for example the Y direction can tell you the height of points relative to the ground plane, and the X and Z modes can be used to measure in-layer thicknesses for 3D printing.
By default when you specify measure points by dragging the mouse, they are unconstrained, and so will be placed at the point on the surface directly below the cursor. In some cases it may be desirable to "snap" these points to salient geometric features. Currently we support a few alternatives. Note that these modes, shown to the right, are identical to those in the Create Pivot tool, and we refer you there for details.