Note - You can explode a arc into regular edge segments
using the Explode Curve context menu item (see the Arc Context Menu Items
section later in this topic).Arc entities are a combination of multiple line segments connected together to approximate the curvature of the arc. These entities act as a single line in that they can define the edge of a face and also divide a face. Additionally, selecting one segment of the arc selects the entire Arc entity. However, all inference techniques will operate on the Arc as though it were comprised of segments. For example, every point on the arc is inferred as an endpoint of the segment. Draw Arcs with the Arc Tool.
Note - You can explode a arc into regular edge segments
using the Explode Curve context menu item (see the Arc Context Menu Items
section later in this topic).
Arc entities are comprised of a length (also called the base chord), bulge, radius, and number of segments. The following image shows an Arc entity.
Note - Arc and Circle
entities are special in that they automatically produce softened edges
when extruded using the Push/Pull
Tool.
You can edit the radius of an Arc entity by using the Move Tool. To edit an Arc entity:
Select the Move Tool. The cursor will change to an four-way arrow.
Move over the Arc entity to locate the midpoint of the Arc entity.
Click and hold on the midpoint of the Arc entity.
Move the cursor to adjust the bulge of the Arc entity.
Click and hold on the starting or ending point of the Arc.
Move the mouse to adjust the radius and length of the arc entity. The radius attempts to stay proportional to the base chord length.
You can also adjust the radius and number of segments using the Arc entity's Entity Info dialog box.
When you use the Push/Pull Tool to extrude a 2D face that includes an arc, it extrudes a special arc Surface entity which can also have its radius edited. Use the Move Tool to reposition the midpoint edge, and the arc curved face set (as well as the midpoints of the two arc entities that define it) will move accordingly.
Arcs with more line segments appear to have smoother curvature than arcs with fewer line segments. However, more line segments increases the size of your model and degrades performance. You can often achieve acceptable results by indicating small segmentation and using smoothing and edge softening to create the impression of smoothness.
If an Arc is deformed in a way that destroys its radial definition, such as with a non-uniform scale operation, it will become a non-parametric Curve entity. Polyline Curves can no longer be edited as arcs.