Overview | Statement List | Example

Swept

Synopsis

obj = BSURF/SWPSRF,TRACRV,obj list1[,ENDOF,obj list2],GENCRV,obj list3[,ENDOF,obj list4][,BLEND,num1][,SPINE,obj1[,ENDOF,obj2]][,ORIENT{,obj3[,ENDOF,obj4]|,xc,yc,zc}][,SCALE{,obj5[,ENDOF,obj6]|,num list}][,TOLER,num2,num3][,RESULT,num4][,IFERR,label:]

Description

Creates a B-surface using sweeping techniques. B-surfaces created in this manner are known as sweep surfaces. A sweep surface is defined as the shape swept out by a curve moving in a prescribed manner along a path in space. The moving curve is referred to as the generator curve because it generates the surface as it moves. The path is referred to as the guide curve because it guides the motion. You can define a sweep surface using either one, two, or three guide curves, and either one or two generator curves.

In the construction of a sweep surface, the directions in which the guide curves were constructed is irrelevant. Instead, the direction of the sweep surface is determined by a point you specify to indicate the starting end of each curve. These points must be specified in a consistent manner (on the same end) for all guide, generator, and spine curves. If you don't specify a point, the direction defaults to the parametric start of the curve.

For a more detailed description of the sweep surface creation techniques refer to the Modeling Help.

Parameters

Parameter	Description
SWPSRF	Minor word indicating that the B-surface is created using a sweep surface technique.
TRACRV	Minor word indicating that guide curves are to follow.
objlist1	An object list containing either one, two, or three guide curves.
ENDOF	Minor word indicating that the directions of the guide curves are to be specified.
objlist2	Point objects used to indicate the starting end of each guide curve specified.
GENCRV	Minor word indicating that generator curves are to follow.
objlist3	An object list of one or two generator curves.
ENDOF	Minor word indicating that the directions of the generator curves are to be specified.
objlist4	Point objects used to indicate the starting end of each generator curve specified.
BLEND	Minor word indicating that a blending method is to be specified. This is necessary when using two generator curves.
num1	A numerical value indicating the blending method to be used between two generator curves. 1 = Linear 2 = Cubic If only one generator curve is specified, the system ignores this information. If two generator curves are specified but no blending method, or an invalid value is entered, the default is Linear.
SPINE	Minor word indicating that the spine curve object is to follow.
obj1	Specifies the spine curve.
ENDOF	Minor word indicating that the direction of the spine curve is to be specified.
obj2	Point object used to indicate the starting end of the spine curve.
ORIENT	Minor word indicating that orientation information is to follow. This is required when only one guide curve is specified. If only one guide curve is specified but the orientation information is not, the method defaults to a Parallel Sweep. If more than one guide curve is specified along with orientation information, the system ignores this orientation information.
obj3	A point, curve, or surface used for constant orientation.
ENDOF	Minor word indicating that the direction of the orientation curve is to be specified.
obj4	Point object used to indicate the starting end of the orientation curve. If the orientation object is not a curve, then the system ignores this information.
xc,yc,zc	Vector components used for constant orientation.
SCALE	Minor word indicating that scale information is to follow. Scale information is required when only one guide curve is specified. If only one guide curve is specified and scale information is not, then the default is a constant scale of 1.0. If more than one guide curve is specified along with scale information, the system ignores this scale information.
obj5	A point or curve used for scale control.
ENDOF	Minor word indicating that the direction of the scale curve is to be specified.
obj6	Point object used to indicate the direction of the scale curve. If the scale object is not a curve, then the system ignores this information.
num list	Numerical list of scale information. The first element in this list is the scale method: 1 = Constant 2 = Linear blend 3 = Cubic blend If the method is constant, then the second element is the constant scale value. If the method is a blend, then the second and third elements are the start and end scale values.
TOLER	Minor word indicating that tolerance values for surface creation are to be specified. If none are specified, the default is the value set in the Unigraphics option Preferences->Modeling. You can also read and set these tolerances using the GPAs &DISTOL and &ANGTOL.
num2	The distance tolerance for surface creation. This value must be positive. This tolerance is the maximum allowable distance between a true theoretical sweep surface and the B-surface approximation that the system produces. This value must be positive.
num3	The angle tolerance for surface creation in degrees. If no value or an invalid value is specified, the default is 0.5 degrees.
RESULT	Minor word indicating that a return variable is to be provided to denote error conditions.
num4	A return variable for error messages. The possible values of this variable and the associated error conditions are as follows:

Return Variable	Error Condition
-9	Invalid scale information.
-8	Invalid orientation information.
-7	Invalid guide curves in obj list1.
-6	Invalid data specifying ends of guide curves in obj list2.
-5	Invalid generator curves in obj list3.
-4	Invalid data specifying ends of gen curves in obj list4.
-3	Invalid orientation information.
-2	Invalid scale information.
-1	Unable to allocate enough memory.
0	Successful sweep surface creation.
1	Unable to intersect guide curve with section plane.
2	No longer returned.
3	No longer returned.
4	Invalid spine curve definition.
5	Reference coordinate system unidentified.
6	Maximum size B-surface exceeded.
7	User abort, no surface created.

These error conditions closely match those of the interactive Unigraphics option. Refer to the Modeling Help for more detailed descriptions.

IFERR,label:

Specifies a label to which program execution jumps if an error occurs.