Extracting a B-Spline Surface

When extracting b-spline surfaces, a mesh lets you visualize the surface. You can add curves from the mesh into the U and V directions for the extracted surface, forcing the surface to fit more closely to the mesh.

You can display a deviation analysis to show the deviation between the mesh and the surface.

To use the mesh to extract b-spline surfaces:

1. Open a mesh file, run the Surface Wizard, and using guided creation, advance to the Surface Extraction PropertyManager.

2. Select a surface, then under Face Settings, click Bspline .

A surface with a mesh appears.

3. Rotate the model to look directly at the surface.

4. Select Display deviation analysis.

The deviation between the surface and the mesh is displayed. A color range legend appears in the graphics area. Surface deviation is around the red, yellow, and green-colored area.

5. To improve surface accuracy:

• Use the U-Dir. and V-Dir. Number of Segments in the PropertyManager to add U and V curves.

Mesh to Mesh Deviation. Add U and V curves before editing the position of curves. Modifying the number of curves automatically repositions all curves.

• Click Editing UV curves. You can then click in two different locations directly on the mesh to create U and V curves.

• Click Editing UV curves, select a curve from the list, then drag to reposition it. Repeat as necessary.

• Increase the number of U and V lines over the area with the highest deviation to try to reduce the deviation.

6. Click Rebuild Surface to incorporate the edits into the surface and review the new deviation analysis.