Void Detection prevents hits from being taken in empty spaces (such as holes). This functionality has been added to these Auto Features:
Auto Surface Point
Auto Edge Point
Auto Line
Auto Plane
Auto Circle
Auto Round Slot
Auto Cylinder
Auto Cone
Without Void Detection, an auto feature may place hits in holes and other empty spaces in the CAD surface and the part.
PC-DMIS uses void detection if your LMS license or portlock has been programmed with the IP measure item. PC-DMIS automatically applies void detection to the generation of the probe hits when you create a supported auto feature by using the parameters from the corresponding Auto Feature dialog box (Insert | Feature | Auto) such as # hits, Start Angle, and End Angle for an auto circle. Any probe hits that would normally fall into a void are moved so that they reside on the surface of the selected feature.
For an Auto Plane feature, you can determine this distance, termed a "boundary offset", from any edge. This boundary offset is specified inside the Void detection area of the Auto Move Properties tab of the Probe Toolbox.
For the other supported Auto Features, this distance is the tip's radius value.
Requested sample hits for Auto Circles or Auto Cylinders are also automatically generated with Void Detection.
The following examples show when Void Detection would be useful for accurately and safely measuring an Auto Feature. Hits denoted with an "X" are determined to be voids and are corrected to the edge of the auto feature surface.
Void Detection for an Auto Plane Feature
Void Detection for an Auto Cylinder Feature
Void Detection can be turned On or Off using the Void Detection toggle on the dialog box. For details on the toggle, see the "Void Detection Toggle" topic in the "Creating Auto Features" chapter.