*linecreatespline

Create a cubic spline curve by interpolating input points.

Syntax

*linecreatespline point_type point_list scond econd svector evector

Type

HyperMesh Tcl Modify Command

Description

This command creates a cubic spline curve that interpolates input points. Various conditions can be used to specify the spline behavior at the endpoints.

Inputs

point_type
Type of entities representing input points. Valid values are nodes or points.
point_list
List ID of the input points or nodes. Minimum of 2 points or nodes must be selected.
scond, econd
Parameter specifying the constructed spline behavior at curve start (scond) or end (econd). Valid values are:
  • 0 - Spline direction at endpoint is not constrained
  • 1 - Spline is closed. In this case any other end condition is ignored. Closed smooth cubic spline is constructed.
  • 2 - Spline direction at endpoint is tangent to direction of input vector svector (for scond) or evector (for econd).
  • 3 - Spline direction at endpoint is normal to direction of input vector svector (for scond) or evector (for econd).
  • 4 - Spline parametric derivative at endpoint equals to input vector svector (for scond) or evector (for econd). Normalized spline parameterization of 0 to 1 is implied.
svector
Vector used to apply boundary condition specified by parameter scond. Only required when scond is 2, 3 or 4.
evector
Vector used to apply boundary condition specified by parameter econd. Only required when econd is 2, 3 or 4.

Examples

To create a closed spline that interpolates nodes 11, 12 and 13:

*createlist nodes 1 11 12 13
*linecreatespline nodes 1 1

To create a spline that interpolates the same nodes, is tangent at its start to vector (0,0,1) and is normal at its end to vector (1,0,0):

*createlist nodes 1 11 12 13
*createvector 1 0 0 1
*createvector 2 1 0 0
*linecreatespline nodes 1 2 3 1 2

Errors

Incorrect usage results in a Tcl error. To detect errors, you can use the catch command:
if { [ catch {command_name...} ] } {
   # Handle error
}

Version History

10.0