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Objects in DInsight models

Programmatically objects (sections) can be accessed via ISection, which controls common properties of an object and gives access to other interfaces related to geometry of the object. ISection of a top-level object of the model can be obtained either via query: KernelCAD>GetModel>IModel>GetSection. ISection of a child object can be obtained from ISection of its parent with a call to GetChild method.

Any object (section) in DInsight model has coordinate axes associated with it, which is called Local Frame of the object. All sections have ShowLocalFrame Boolean property, which controls visibility of the local frame If ShowLocalFrame is true, local axes are rendered in 3D views with triangular pointers. Programmatically ShowLocalFrame can be managed via ISection2 interface.

Available types of objects include:

2. Surface Of Revolution (SOR)

3. Mesh Section

4. Line Strips

5. Point Sets

6. Pipes and Curved Bars

7. BRep Sections

8. Overlays

9. BSpline BRep Sections

Notice: This list may be incomplete for versions later than 5.0

Types 1 to 8 are called native to KernelCAD mostly because of historical realsons

Objects of 3DS, SOR and Pipe type, have property called Geometrical Resolution. Geometrical resolution is a positive integer which determines how fine is approximation of the surface. Increasing this number leads to a better surface rendering, but also increases computational load on the machine. Common practice is to make modifications of geometry in low resolution which can be selected from few trials. On final stage the surface can be displayed in high resolution. Geometrical resolution is set on per object basis and is saved with the model. Geometrical resolution of the object can be modified through Options dialog, accessible via Menu > Current Object > Options in 3D Debugger. Programmatically it is accessible via ISection interface.

Note that reducing the resolution is a valid modeling technique, which can offer a better rendering of the model. This is the case when modeling soft objects like cushions in furniture or when the object has too many edges which need to be made smooth. Se also Modeling Tips.

Sections keep array of child sections. Query IArray or IArray2 from ISection to manipulate array of children of the section programmatically. A number of methods of IModel2 (Add(), AddNewItem() etc.) provide shortcuts for manipulation of the child section array

Sections are Items which have some geometry (surface, points of other properties which have parameters or coordinates) and local frame.  The above array is separate from Array of Items

To modify color and reflective properties of an object, which has surface, query IMaterial from the relevant ISection.Color of line strips and point sets is set directly via ISection>ISectionPointSet>GetColors()>IMatrixData>Set*(). It can be variable

To obtain dimensions of an objects access Bounding Box property of the section. It represents the smallest axis-aligned box containing the section.

Sequence ISection > IObject_KC > Copy(iObject_KcOfAnotherSection) allows copying local frames and other attributes like material between sections. This operation does not copy geometry (meshed or parametric surface, lines or points) of the section

Parameters of native KernelCAD objects

Geometry of an object is defined by a set of relevant values, like coordinate of a point in cross-section of a line or position of an axial knot. These numbers, which have some geometrical meaning in DInsight models are called Parameters. Programmatically parameter values are represented by numbers of type double. Parameters belonging to different objects ( like different edges of a surface patch ) are considered different. Parameters are those values, which are accessible via edit boxes in 3D Debugger. Programmatically parameters are accessed via IElement interface. Mesh Sections are not considered parametric objects.

See also: KernelCAD Models, IMetrics, IBox