|Up to now, you have learned how to create edges out of 3D curves.|
|You will now learn how to create an edge out of a 2D curve and a surface.|
To learn this aspect of Open CASCADE Technology, you will build helicoidal profiles out of 2D curves on cylindrical surfaces. The theory is more complex than in previous steps, but applying it is very simple.
As a first step, you compute these cylindrical surfaces. You are already familiar with curves of the Geom package. Now you can create a Geom_CylindricalSurface cylindrical surface using:
- a coordinate system
- a radius
Using the same coordinate system neckAx2 used to position the neck, you create two cylindrical surfaces Geom_CylindricalSurface with the following radius:
Notice that one of the cylindrical surfaces is smaller than the neck. There is a good reason for this: after the thread creation, you will fuse it with the neck. So, we must make sure that the two shapes remain in contact.
Handle(Geom_CylindricalSurface) aCyl1 = new Geom_CylindricalSurface(neckAx2 , myNeckRadius * 0.99);
Handle(Geom_CylindricalSurface) aCyl2 = new Geom_CylindricalSurface(neckAx2 , myNeckRadius * 1.05);