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Collision C# Sample

Source code for Collision sample is available in Samples\NET\C# folder of the installation directory. It is recommended to copy the folder to location outside of the installation folder.

See also Collision detection, Metrics Sample, All samples

Implementation

All KernelCAD related functionality is implemented inside the CollisionForm 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.

OnMoveObject() Move button handler sets up timer for animation and calculates step vector for each animation step and stores it in m_dAnimationStep variable. On every animation step OnTimer timer event handler increments the current object position and calls IMetrics.IsCloserThan to check whether the collision situation occurred. If IMetrics.IsCloserThan has retuned true, the handler stops animation with a line animationTimer.Enabled = False and calls CalculateDist Sub to process collision situation.

Inside the CalculateDist Sub, identical to one from Metrics Sample, exact distance between the objects and two nearest points are calculated using IMetrics.Dist. The calculated nearest points are displayed in 3D view with red points. To improve performance of rendering IRelation obtained in CalculateDist is converted once to a list and stored in m_pairList member. This work is done by CompileNearestData method, 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(), to add custom drawing of nearest points to the scene. The drawing is performed inside OnClientDraw handler. In the OnClientDraw method the coordinates of each vertex are obtained via IVertex.GetVertexCoord.