#### Specifying Collision Tolerances

Collision tolerances are specified in the Collision Tolerance dialog box. This dialog box can be activated by clicking the Tolerances button in the Probe Utilities dialog box.

In the edit box, you can specify a positive or negative value for each probe component selected from the drop-down list. This effectively changes the size of that component.

- A positive number will increase the size of the component so a collision will be detected if that component comes within the specified distance of the part.

- A negative distance decreases the size of that portion of the probe, having the opposite effect of a positive distance.

You can also choose to ignore a probe component by selecting the Ignore check box. PC-DMIS will then ignore that probe component when checking for collisions. This may be useful with a tip, where collisions are expected to occur when taking hits.

Once you start collision detection by selecting the Collision Detection menu option, PC-DMIS's internal CAD engine performs all the calculations required to detect a collision. Any collisions detected are displayed in the Collision Detection dialog box. This dialog box reports the results in the Probe Display window of the dialog box, and saves them for later use in drawing the Edit Path lines.

See “Detecting Collisions” in the "Editing the CAD Display" chapter in the PC-DMIS Core documentation for additional documentation regarding the Collision Detection option.