During clash detection, the graphic elements of one object is compared with the graphic elements of other objects in the same model and in other models. The geometry hidden in a view is not included in clash detection.
The results are evaluated to determine if the surfaces or edges of one object intersect those of another object. If interfering objects are detected, they are recorded for your review. The results of the clashes are shown as either a hard clash or a clearance. These calculations also are compared to the tolerances that you specify in the object set
Clearance and Clash Detection
Clearance allows you to expand the space around an element so that the extra area can be calculated when executing a clash detection. For example, if you want to detect clashes between pipes and metal, you can add a clearance value to the pipes to allow for insulation around the pipes.
Types of Clashes
There are two types of clashes: hard clash and clearance.
- A hard clash is a physical clash between elements. If the graphic elements from two different objects intersect, then a hard clash is reported.
- A clearance checks for a clash taking into consideration the added area around the physical element. If any part of a graphic element from one object lies within a specified distance of another object, but does not intersect any of the graphic elements of that object, then a clearance is reported.
Tolerance and Clash Detection
Tolerance is the range of variation permitted in maintaining a specified standard when designing.
The Tolerance value is set in the Advanced Settings dialog, which opens when you select from the Clash Detection dialog. The default value is set to 1 mm; the maximum value is 10 cm. If the units of the active model are not set to mm, this value will be different.