byRhinoGadget - SetPtLinear, SetPtLinear3D, SymmetricCrv, SymmetricSrf, SymmetricDiagonalSrf

SetPtLinear command aligns control points in a straight line based on the construction plane. Unlike SetPt, you can specify the alignment direction, making it easy to align them diagonally in addition to orthogonal directions. The control point's height relative to the construction plane is preserved.
SetPtLinear3D command aligns control points in a straight line. It can be used to align control points in the desired direction, such as aligning specific control points to create a G1 (tangent) connection or editing control points to create a straight line shape.
SymmetricCrv command aligns the control points of a curve symmetrically. It is used to create a symmetric shape as a single curve that is not divided at the center axis. If the number of control points is odd, the center control point will be located on the axis. For periodic curves, place the curve's seam near the center before using the command.
SymmetricSrf command aligns the control points of a surface symmetrically. It is used to create a symmetric shape as a surface that is not divided at the center axis. If the number of control points is odd, the center control point will be located on the axis. For periodic surfaces, place the seam near the center before using the command.
SymmetricDiagonalSrf command aligns the control points of a surface symmetrically in the UV diagonal direction. It can be used only if the number of control points in the U and V directions of the surface control points is the same. The symmetry direction is set from the origin of the UV plane, so if the desired direction is not obtained, use the Dir command to change the direction of U or V and then execute the command.