Creating a Simple X-Topology Surface

This section of the tutorial creates a X-Topology surface based on a simple rectangular network of curves

43. Create a new file.

44. In the attributes Panel (PolyCAD Options), within the Manipulations Options group, set up a grid spacing of 2.0m with a Major (grid) Frequency of 10.

45. Make sure that the editing options on the status bar indicate that the Grid, Grid Snapping, Object Snapping, Enhanced 3D Editing and Highlighting are turned on.

46. Create a new X-Topology curve from the Create menu, (Create -> X-Topology Curve).

47. Draw a curve with three control points starting at the origin.

48. With one point half way up a major grid square, (0, 10, 0).

49. Finishing up at the top of a major grid squard, (0, 20, 0).

50. Create another X-Topology curve with three control points on the other side of the major grid square, X=20.0m.

52. Now join the two curves, first with an X-Topology curve at the bottom of the first curve (the direction of the curves does not actually matter to the modeller), snapping to the control point.

53. With a control point halfway along the bottom of the major grid square and finishing by snapping to the control point at the bottom of the second curve.

54. Repeat the process to join the other ends of the first two curves, starting by snapping to the control point at the top of the first curve.

55. A control point should be place halfway along the major grid square and finishing off by snapping to the top of the second curve.

56. Now select all the curves by dragging a rectangle or by pressing Ctrl+A.

57. With the curves selected, an X-Topology Surface (XTSurface Group) can be created from the Right-Click menu, (Right-Click -> Multiple Selection -> Create XTSurface Group).

A surface will now be created by filling in the the faces (holes) formed by the curve intersections.

58. Select the new X-Topology surface... show the surface options in the attibutes panel. The Definition Curves group highlights all of the curves involved in the definition of the surface. Within the Surface Patch Type group, different techniqus for forming the surface can be selected. Each has different properties such as different levels of continuity between patches or will produced certain CAD entities when exported from PolyCAD.

Refining the Surface Definition >>>