The following group codes apply to spline
entities. In addition to the group codes described here, see
Common Group Codes for Entities.
For information about abbreviations and formatting used in this
table, see
Formatting Conventions in This Reference.
Spline group codes

Group code

Description

100

Subclass marker (AcDbSpline)

210

Normal vector (omitted if the spline is nonplanar) DXF: X value; APP: 3D vector

220, 230

DXF: Y and Z values of
normal vector (optional)

70

Spline flag (bit coded): 1 = Closed spline 2 = Periodic spline 4 = Rational spline 8 = Planar 16 = Linear (planar bit is also set)

71

Degree of the spline curve

72

Number of knots

73

Number of control points

74

Number of fit points (if any)

42

Knot tolerance (default = 0.0000001)

43

Controlpoint tolerance (default = 0.0000001)

44

Fit tolerance (default = 0.0000000001)

12

Start tangent—may be omitted (in WCS) DXF: X value; APP: 3D point

22, 32

DXF: Y and Z values of
start tangent—may be omitted (in WCS)

13

End tangent—may be omitted (in WCS) DXF: X value; APP: 3D point

23, 33

DXF: Y and Z values of
end tangent—may be omitted (in WCS)

40

Knot value (one entry per knot)

41

Weight (if not 1); with multiple group pairs,
they are present if all are not 1

10

Control points (in WCS); one entry per control
point
DXF: X value; APP:
3D point

20, 30

DXF: Y and Z values of
control points (in WCS); one entry per control point

11

Fit points (in WCS); one entry per fit point DXF: X value; APP: 3D point

21, 31

DXF: Y and Z values of
fit points (in WCS); one entry per fit point
