Surfaces > Combine Surfaces
 
 
 

Creates a single new surface from several separate surfaces.

Overview

Often it is easier to model a complex shape with several surfaces, rather than one large surface.

However, these kinds of composite surfaces cannot be used in some circumstances. You may want to use a tool that only works on single surfaces, or your manufacturing system may require a single surface.

The Combine Surfaces tool allows you to combine several surfaces into one surface. It has the following limitations:

To combine several surfaces into one new surface

  1. Click the Combine Surfaces icon, or choose Surfaces > Combine Surfaces from the tool palette.
  2. Pick the surfaces you want to combine.
    • As you add surfaces, the surface boundaries change color. Green means the current group of surfaces has a four-sided boundary and can be combined. Yellow means they cannot be combined.
    • When the surfaces can be combined, an arrow appears showing the normal of the new surface. Click the arrow to reverse the normal of the new surface.
  3. When you have picked all the surfaces you want to combine and the boundary is green, click Go.
  4. The system prompts you to click the edges that must be continuous with adjacent surfaces.
    • Click a green boundary line to mark it for tangency with adjacent surfaces. A label appears on the boundary.
    • Click the label to change the continuity type. Each click cycles through positional (pos), tangent (tan), and curvature (cur).
  5. Click Go.

How the function works

  1. Combine Surfaces fits four curves to each of the four outer boundaries of the set of surfaces you selected.
  2. Then, it places a simple surface, of the degree you selected in the option box, within those four curves.
  3. The function samples the interior of all the selected surfaces and modifies the surface to match those samples.
  4. If the surface doesn’t match well enough, Combine Surfaces inserts knot isoparametric curves into the simple surface to allow for finer adjustments to the shape.
  5. If you selected continuity with boundary surfaces, Combine Surfaces samples those surfaces as well, and increases the samples along the outer boundaries of the original surfaces.

Tips and notes

Combine Surfaces Control

Tolerance

Controls the fit distance of the combined surface to the original surfaces.

Angle Tolerance

Controls the fit angle of the surface normals at sample points.

Iterate to Tolerance

Increases samples and insert more isoparametric curves until the tolerances are reached.

Explicit Control Options

U Degree/ V Degree

Specifies the degree of the resulting surface in U and V directions.

U Max Spans/ V Max Spans

These sliders only appear when Iterate to Tolerance is off.

Does not create a combined surface with more than the given number of spans in the U and V direction, even if the tolerances are not reached.