This registry entry determines the aperture radius, in pixels. This radius controls whether a ray is close enough to an edge for the edge to be selected from the ray hit.
The intersection algorithm used by the PC-DMIS Direct CAD Interface for selecting and piercing Creo part geometry returns a list of ray intersections with a model. It computes the intersection points of both the original ray and its "negative" with the geometry of the model. The output array is sorted in order of increasing signed distance. You must determine whether the ray is inside or outside the model.
If a ray hits in the middle of a face on the model, the algorithm selects the face. However, if the intersection point is very close (within an internally determined selection aperture) to an edge, then the algorithm also selects the edge. Thus, more than one entry of type surface or edge in the ProSelection array may correspond to one actual piercing of the model by the ray. These multiple selections can decrease computation and comparison time.
The smaller the aperture radius, PC-DMIS returns fewer intersections. This can improve computation and comparison time.
Entry Name: ApertureRadius
Entry Type: Real Number that specifies the aperture radius in pixels. If the value is less than or equal to 0 (zero), then the function uses the default aperture radius of seven pixels, or the current value stored in the configuration file. The default value is -1.
For additional information about the configuration file or this particular algorithm, see your Creo toolkit's documentation.