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Cross View Sample

The sample demonstrates different methods of calculation and display of intersection of 3D objects with a 3D plane.

Running the application  

The application has two KernelCAD components on the form. The left control shows model of a pipe. The control on the right-hand side shows cross-section of the pipe with a plane.

Plane is rendered transparent in the left control. Position and orientation of the plane can be set arbitrary using Location and Normal edit boxes.

The Apply button updates position of the plane in 3D view

"Update Cross-Section View" button recalculates the intersection line and displays in in the right hand side control.

The implementation group gives choice of three different methods of calculation and display of the intersection.

The control on the right-hand side is pure two dimensional view when High or Mid implementation is chosen. In Low implementation mode the control in the right is three dimensional, but rotation is disabled so it is effectively two dimensional display. Pure 2D mode renders a grid to show dimensions and position. Advantage of Low level mode is that the 2D view has zoom and pan operations.

The "Approximate X Axis" group defines direction of x axis in the plane. Changing the direction will appear like rotation of 2D view around center of the window. Orientation of axes of the 2D View Frame inside the plane is shown using small axes in 3D View

Application Design

The application demonstrates three different methods of implementation: High, Mid and Low Level.

High level implementation involves the minimal amount of programming. The 2D picture is generated automatically.

Mid and low level implementation offer on the other hand more flexibility for possible modifications of the displayed scene and demonstrates access to coordinates of points on the line.

In Mid and Low level mode the intersection line is calculated in UpdateCrossSectionView() of the form/dialog using IBoolSectionEx.Execute with operation parameter set to EBooleanOperation.eBoolOpInters

Mid level implementation adds intersection line directly to the 2D View using Direct Definition method.

Low level implementation creates replicas of intersection lines using IObject_KC.Replicate and adds them without a change to 3D model of the control on the right hand side. To simulate two dimensional view Eye Frame of the view is modified to align it with normal of the cross-section plane in LowImplementation.AlignViewPlane(). Scene rotations are disabled in Init() method of the form/dialog

Implementation

C++

Visual Basic 6