VB .NET Metrics Sample
Metrics Visual Basic .NET Sample
Metrics is an .NET Windows Forms application, which demonstrates calculation
of distances, and nearest points between two objects and usage of
IMetrics.Dist method.
Source code for Metrics sample is available in Samples\NET\VB folder of
the installation directory. It is recommended to copy the folder to location
outside of the installation folder.
Description
Implementation
All KernelCAD related functionality is implemented inside the MetricsForm
class. The KernelCAD related data is initialized inside InitModelInfo()
method, which uses GetModel
method of the KernelCAD control to obtain the root
interface of the hierarchy. ISection
interfaces, representing generic KernelCAD object, are obtained for the first
two top level objects of the model with the help of
IModel.GetSection and stored in
m_iSectionFrom and m_iSectionTo member variables.
Calculation of distance is performed in buttCalculate_Click handler,
where IMetrics
interfaces are queried from relevant ISection
and IMetrics.Dist is called. The result of
the calculation is listed by returned IRelation
interface.
In this application the calculated nearest points are displayed in 3D view
with line segments and points. To improve performance of rendering
IRelation
is converted once to a .NET List and stored in m_pairList member.
This work is done by CompileNearestData Sub, where pairs of the relation
are iterated through, correspondent elements of the each per object list are
retrieved and converted to the actual type of IVertex.
The application uses ClientDraw
event, requested in OnFormLoad Sub, to add custom drawing of shortest
segments and other elements to the scene. The drawing is performed inside
OnClientDraw handler. In the OnClientDraw Sub the coordinates of each
vertex are obtained via IVertex.GetVertexCoord.
When rendering of normals, is requested they are obtained with a
IVertex.GetNormal call in
DrawNormals.
Work related to the "Is Closer than" group of controls is done in
OnCalculateCloserThan handler with the help of
IMetrics.IsCloserThan method.
Note that movements of the current object are performed in OnMoveObject
via IFrame2
rather than IFrame
to make movements relative to the current axes.
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