About Spatial Query

Large assemblies can be complex, consisting of many products and sub-products. You can simplify a complex assembly by displaying only those products you want to work with. Spatial Query lets you do just that.

How it works

The proximity query calculation is not based on the representation visualized in your session. Rather, it is based on a cubic representation of each part, the size of the cubes of which is designated by the accuracy parameter. Because of the way in which the detection algorithm is designed, the real distance between two parts in the visual representation could be greater than the clearance parameter you specify, yet the two parts could be sufficiently close as to be considered neighbors. An increase of the clearance value can be due to:

the cubic representation of the parts:   maximum increase=2*accuracy*sqrt(3)
the positioning error: maximum increase=0.5*accuracy*sqrt(3)
the clearance value transformed into cubes: maximum increase= accuracy*sqrt(3)

The sum of above three deltas gives a maximum increase= 3.5*accuracy*sqrt(3).

In the example below, the proximity query was made using an accuracy parameter=30mm and a clearance parameter=0 mm, yet two parts separated by a distance of ~46 mm were considered to be touching, therefore neighbors.


Cache Management and Accuracy:
Setting an accuracy determines the size of the cubes used to represent the products in the calculation. For larger products, a lower setting will result in a slower computation time but a more precise result.

Clicking opposite Accuracy gives you access to the Cache Management and Accuracy dialog box which tells you how much cache is used, lets you free the cache, and if you have a DMU Navigator license only, will calculate the cache required for an accuracy setting you enter.


Setting a clearance defines an area around the reference selection within which all nearby products or outside of which all far away products are returned by the query depending on the Products to Select option chosen.

What About Released Accuracy?

The default value for released accuracy is 20mm.
This value can also be defined by the administrator.

How does the administrator define the release accuracy value?
  • he sets a precise and required value in the release Accuracy field. 
    Tools->Options->Infrastructure->Product Structure->Cache Management-> Proximity Query)
  • then runs CATDMUUtility batch process without defining - vox  option, the release accuracy value is taken into account. The data is pre-tessellated. 
  • you as user can select this value checking the Release accuracy option when performing proximity query


You can combine the Spatial Query command with other DMU commands, for example Comparing Products (in the DMU Space Analysis toolbar).