In SurfaceWorks, we build up complex
from simpler ones. Everything rests on a foundation of points. Curves are created from
points in several different ways, and surfaces are created from curves in several
different ways. A special kind of curves are Snakes, which are curves constrained
to lie precisely in the surface they belong to.
- The Arc is a circular arc, defined by 3
points and passing through at least one point. The arc lies in the plane containing
the 3 points. The 6 types of Arc include the arc through 3 points, tangent arcs,
semi-circles and circles.
- A B-spline Curve is a continuous curve
defined by a series of control points. The curve is formed in relation to the 3D polyline
joining the points in sequence. The B-spline Curve always starts at the first control
point and ends at the last control point, and it is always tangent to the polyline at
these end points, but in general it does not pass through the other control points.
Instead, it is "shaped" by them into a continuous imitation of the
- The B-spline Snake is the counterpart of the
B-spline Curve, constrained to lie in a surface.
- A C-spline Curve is a continuous curve
defined by a series of control points. The curve ends at the two end control points and
passes through the others in sequence.
- The C-spline Snake is the counterpart of the
C-spline Curve, constrained to remain in a surface.
- The Edge Snake is a special line snake lying
along one complete edge of a surface.
- A Foil Curve is a true NACA
airfoil section. Foils can be constructed with 3, 4, or 5 control
points — 3 for a half section, 4 for a symmetric full section, or 5
for a cambered or symmetric full section.
- A Helix has a starting point, uses a line as
its axis, and its slope is controlled by pitch.
- An Intersection Snake is a curve on a
surface, located where a cutting surface intersects the surface.
- A Line is the simplest type of curve,
connecting two points.
- There is also a Line Snake, the counterpart
of the Line, but constrained to lie in a surface.
- A Mirrored Curve is a curve created by
reflecting a given parent curve across a specified mirror entity onto a mirror (a
plane, line, or point entity).
- A PolyCurve is a single curve made by
joining two or more other parent component curves end-to-end.
- A Projected Curve is a curve formed by
projecting a specified parent curve onto a mirror (a plane, line, or point
entity). Each point of the curve is projected normally (perpendicularly) onto the mirror.
The Projected Curve therefore lies entirely in the mirror.
- There is also a Projected Snake.
- A Relative Curve is a curve formed by
offsetting points from a parent curve. If the parent curve is moved, the Relative Curve
moves in an exactly similar way, so as to maintain its specified distance and direction
from the basis curve.
- A SubCurve is a portion of a parent curve.
- A SubSnake is a portion of a parent snake.
- The UVSnake is a special line snake
traversing a surface at a constant value of the u or v parameter.