IMetrics(64) Interface
 Dist
 GetDimensions
 GetPointLocation
 IsCloserThan
This interface obtains the size of the model. Warning: IMetrics can be
expanded (but not changed) in future releases.
IMetrics can be queried from IModel,
ISection and possibly other obejcts in intermediate
updaes and releases. Attemp to query this interface from an object to check if
the obekct implements th einterface.
When queried from IModel this interface returns results
related to the whole set of objects. For example GetDimentions() method returns
bounding box of the whole model.
See also: Metrics Sample,
Collision detection,
Collision Sample,
Interface List
HRESULT Dist( IMetrics * iIMetricObj,
MetrDistContext* context,
IRelation** nearest, double* dist )
Parameters
iIMetricObj  [in]
IMetrics interface implemented by the second
object. See remarks.
context  [in] NULL reference or
MetrDistContext
structure containing additional parameters. When the reference is NULL all
defaults are used. See remarks.
nearest  [out] If nearest is not a
NULL reference, a
IRelation will be retuned in the
referred variable. Lists referred to by the
relation nearest
keep elements of type IVertex. See remarks.
dist  [out] Returned distance between the objects

 Remarks:
See also IMetrics2.Dist for a simplified version of this method.
The method calculates the distance between the object implementing the interface and
the object where iIMetricObj was queried from. Distance is the shortest distance between any two points belonging to the
objects.
The returned nearest interface can be used to
investigate set of pairs of mutually nearest points from the two objects.
The size of the set depends on options supplied in the context
structure. In the simplest (default) case if context .needAll =
false the set consists of a single pair of two nearest points. When
there are more than one nearest pair at exactly the same distance, selection of
the returned pair is random.
When context.needAll is set to
true and d is the minimal distance retuned by the
method the set will contain all pairs at distances in range d to
d+context.tolerance. Note that when there
are infinite numbers of nearest points, like in the case of parallel planes, only
a finite
number of distinct ones are selected. This selection depends on the geometry of mesh
of the surface.
includeChildren member of context is
true children of both objects are considered as part of the object.
To obtain information about particular point, call IRelation.GetRelation
method of the nearest interface to obtain list of all
pairs. Browse the list using its
IIterator interface. Retrieve the required pair with
a call to IList.GetAt of the list of pairs and cast it to
AssociationPair type. Use the obtained posn0 position to
obtain IVertex interface from the first list of the nearest
relation. The first list is returned from call to IRelation.GetItemList(true)
of the nearest
IRelation interface. It contains
elements of type IVertex. IVertex interface can be
used to obtain information about coordinates as well as normal(s) to the surface
at the point.
Elements of the pair list are sorted by increasing distance. The nearest two
points are listed first. The order is random for pairs at exactly the same
distance.
Note 1: that this method is computationally intensive for large
models. It is recommended to avoid calling it in a tight loop with context.needAll
and/or context.includeChildren set to true. Consider using the
IsCloserThan method in this situation instead.
Note 2: The algorithm assumes that the objects do not have internal
interentity, i.e. they do not have common points which belong to strictly
internal area of both objects. If this happens the algorithm may return
incorrectly small positive number.
HRESULT GetDimensions( DIPoint* min, DIPoint* max )
Parameters
min  [out] 3D point in global
coordinates (See DIPoint). Coordinates of min a are minimal values of the coordinate for any
point in the model.
max  [out] 3D point in global
coordinates (See DIPoint). Coordinates of max a are maximal values of the coordinate for any
point in the model
Return Values

 S_OK in case of
success.

 Remarks:
This method returns opposite diagonal corners of the minimal box totally
containing the model.
HRESULT GetPointLocation( DIPoint* pt, int* location
)
Parameters
pt  [in]
point location of which is to be found
Coordinates must be relative to the local frame of the box if the box is
oriented or global is the box does not have a local frame
location  [out, retval] The returned location code.
See remarks

 Remarks:
Identifies location of the point. The object
where this interface was queried from is assumed to be solid (has closed
surface). Meaning of the returned location code
depends on type of the object, which implements the interface.
In this release this method implemented only by
Entities with Mesh Geometry and Oriented Boxes.
Mesh Entities
pt
must have global coordinates. Return codes:
 1  Invalid location (error code)
 0  inside internal area of the solid, not on the surface
 1  Outside not on the surface
 2  Coincides with a vertex
 3  Lies on an edge of the mesh
 4  Inside a face of the mesh
Notice that codes greater than 1
indicate that point lies on the surface.
Oriented Boxes
Coordinates of pt
must be relative to the local frame of the box if the box is oriented or global
is the box does not have a local frame. See
Location codes for boxes
for the return codes.
HRESULT IsCloserThan( IMetrics * iIMetricObj, double dist,
MetrIsCloserThanContext*
context, VARIANT_BOOL* closer );
Parameters
iIMetricObj  [in]
IMetrics interface implemented by the second
object. See remarks.
dist  [in] Value to compare the distance to.
context  [in] NULL reference or
MetrIsCloserThanContext
structure containing additional parameters. When the reference is NULL all
defaults are used. See remarks.
closer  [out] The returned Boolean value. True if
the objects have points closer than dist and false
otherwise.

 Remarks:
The method returns true if the distance between object implementing the
interface and the object where iIMetricObj was
queried from is less than dist.
If includeChildren member of context is
true children of both objects are considered as part of the object. . Default:
false
If further member of context is
true the method will solve the opposite problem: Return true if there are two points
in the objects, which are have distance greater than dist. Default is
false
quickCheck member of the context
structure allows significant acceleration of the algorithm when two object are
either convex or at distance greater than maximal distance between any two
adjacent vertexes of the mesh. Set it to false is not sure. It should be true if
it is expected that some straight line between any two points of one object can
intersect with another object.
This method is supplied as alternative to Dist
method for applications like collision
detection. In most cases it offers better performance. For collision
detection it is recommended to use calls to this method between changes in the
object(s) position or orientation. If needed, once the method returns false
(collision) the Dist method can be called to
retrieve information about the nearest points.
Note: The algorithm assumes that the objects do not have internal
interentity, i.e. they do not have common points which belong to strictly
internal area of both objects.
See also: Collision detection,
Collision Sample
