KOMPAS-3D v23

A surface spline is a spline located on the theoretical surface of the selected face. The theoretical surface of the face is extended if needed. For more details on the theoretical surface of the face, see section Parametric Representation of the Surface. Isoparametric Curves Add-Ons Curves and Surfaces.

There are two types of a surface spline: spline by vertices and spline by poles.

A spline by vertices passes through the points defined by the user.

To plot a spline by poles, you need to set the vertices of its characteristic broken line.

Boundary points of the spline coincide with the terminal vertices of the broken line; the first and the last segments of the broken line are tangential to the spline in the start and in the end points, respectively. Other vertices of a broken line are the poles of the spline. The points of the spline do not coincide with the poles, but are located at some distance from them. This distance depends on the weight of each pole. The weight of spline points can take values in the range from 0.0001 to 999. More details on the weight of points...

To plot a surface spline, use the Surface Spline command .

Step-by-step instructions

1.Select the spline plotting type: closed or open. To do this, use the Close Curve option.

2.In the graphic area, select the face to place the spline on.
This face is highlighted. The name of the selected object is displayed in the Surface field on the Parameter Panel.

For more details on selecting objects, see section General Information on Objects Selection.

3.Select the spline type using the Type group of buttons:

Spline by Vertices,

Spline by Poles.

4.Set the first point of the spline. To do this, you can use the following methods.

•Select the position of the point in the graphic area with the mouse.

•Enter the U and V parameters into the UV parameters, % field of the Vertex Design group on the Parameter Panel.

•Select a point object. You can select an object in the graphic area or in the model Design Tree. It should belong to the specified face and should be located within its boundaries. You can use the following as a point object:

•vertex of a face edge,

•vertex of an object (or a point in space).

After you specify a point, its U and V position parameters are entered into the point parameters table.

If you select a point object when defining a point, an associative link is automatically created between this object and the resulting spline point. It is marked with a check mark in the point parameters table. When you select a spline point, the name of the related object is displayed in the Snap Point field. You can delete the link if needed. More details on associative links...

5.Set the other spline points in the same way.
When defining points, you can view their parameters: for a newly defined point — in the Vertex Design group of elements, and for already defined points — in the point parameters tablelocated in the Vertex Coordinates group.

A phantom of the spline with current settings is displayed in the graphic area.

6.When you plot a spline by poles, you can set the weight of the vertices of its characteristic broken line in the Weight field. You can set the weight before the vertex is defined or afterwards, when editing its parameters (see the next section for more details on the editing mode).

7.If you need to edit the spline configuration, switch to the editing mode. In this mode, the following actions are available:

•move or delete the points, create points in the existing segments of the spline

Changing position of points

Adding and deleting points

•modify the spline shape in points using matings or tangent vectors

Spline mating with curves on surface

Managing the tangent vector

•for spline by poles: change the weight of any vertex. To do this, select a vertex and enter the required weight value in the Weight field. The pole weight can also be set in the Weight column of the point parameters table.

After making changes, you can continue specifying points by returning to the Creation mode.

8.If necessary, set the name, color and display parameters of the created spline in the Properties section on the Parameter Panel.

9.To complete creating the spline, click Create Object button .

The spline will appear in the graphic area on the selected face, its icon will appear in the Design Tree. The set points of the spline will also be displayed in the Tree. They are subordinate to the spline.

10.To complete operation of the command, click Finish .

Tips

To set the linear and angular parameters, you can use the commands of the geometrical calculator.