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:
- The combined outer boundary of all the
surfaces must have exactly four sides.
- Combine surfaces does not work on trimmed
surfaces.
To combine several surfaces
into one new surface
- Click the Combine Surfaces icon, or choose Surfaces
> Combine Surfaces from the tool palette.
- 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.
- When you have picked all the surfaces
you want to combine and the boundary is green, click Go.
- 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).
- Click Go.
How the function works
- Combine Surfaces fits
four curves to each of the four outer boundaries of the set of surfaces
you selected.
- Then, it places a simple surface, of
the degree you selected in the option box, within those four curves.
- The function samples the interior of
all the selected surfaces and modifies the surface to match those
samples.
- 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.
- 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
- Using very tight tolerances does not
guarantee that the resulting surface will match the original surfaces
with higher accuracy.
Combine
Surfaces tries to achieve tighter tolerances by:
- increasing sampling, and
- inserting more knot isoparametric curves
for finer control.
The result is often a surface with more complexity
than you need.
- This tool can often achieve good fits
with relatively loose tolerances. If you relax the tolerances, it
also reduces the time it takes to create the new surface.
Try using loose tolerances
to begin with, and increase them if you are not achieving the accuracy
you need.
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.