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Plotting of linear surface by curve with tangency to surface |
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To plot a linear surface using a curve and a surface, which must be tangent to the resulting surface, you can use the Linear surface along a curve with tangency to a surface command 
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Step-by-step instructions
1.Specify the curve along which the segment-section will move. The starting point of a segment will be located on this curve in any position.
The following can be specified as a curve:
•a spatial curve or, in the case of a contour or a broken line, individual segments,
•sketch line or entire sketch (indicating the entire sketch is possible if it contains one object or one chain of objects),
•edge,
•a chain of the above objects in any combination (objects are specified in their junction order).
Face edges, sketch lines, and polyline segments are specified in the model graphic area. To select the entire sketch or broken line, specify this object in the Design Tree or select all the sketch lines or all the segments of the broken line in the graphic area. A spatial curve can be specified both in the Design Tree and in the graphic area. Specifying curves with subordinate objects-curves have Features.
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Plotting a linear surface is possible, if a section plane intersects a base objects (a curve and a surface) and within that plane you can plot a tangent to a curve of intersection of a base plane and a section plane through a point of intersection with a base curve (see the Drawing scheme). |
The name of the selected object(s) (or objects if you specify a chain) is displayed in the field Curve of the Parameter Panel.
2.Specify the surface that the section-segment will touch. For this purpose, activate the Surface field and specify a non-flat face of a solid/surface or coherent set of faces a single solid or a single surface.
To choose a whole solid or surface, specify it in the Design Tree or select all elements of the solid/surface using the Marquees in the graphic area. A linear surface will be plotted through all the faces of the selected solid or surface, which are located within plotting conditions. Later the plotting result will be changing according to changes in faces number.
If necessary, you can specify several non-coherent faces or faces sharing common edges but belonging to different solids/surfaces. In this case plotting produces not one, but several linear surfaces (according to number of faces satisfying the plotting conditions). After the command finishes, you can select surfaces to keep in the model (see below).
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It is permissible to have faces, not complying to the plotting conditions, in the list of selected faces. They are simply ignored in the plotting process. If in the future the shape and/or position of the faces change in such a way that the construction condition will be met, then the resulting ruled surface will change too. |
Names of the selected objects are displayed in the field Surface.
When you finish selecting a curve and a surface, a phantom of a linear surface being created with default settings is displayed in the graphic area.
3.Specify an object defining the orientation of the section plane during the movement of the segment. To do this, use controls of the Design section. The type of movement can be selected using the Section Movement. The following options are available:
Parallel to itself — while moving, the segment in each position is in the plane perpendicular to the straight-line direction set by the guiding object (Figure A).
Along the line — the segment in each of its positions is in the plane perpendicular to the specified guiding line — a curve of arbitrary shape (Figure B).
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a) |
b) |
Different types of section segment movement provide different results:
a) parallel to itself, b) by line
Types of objects used to define the section plane orientation, and the order of their selection are described in the section Objects Defining Orientation of the Section Plane During Movement of the Segment-Section.
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The object to define the section plane orientation should be selected in such a way that this plane intersects with the curve and surface objects specified for plotting. Otherwise it's impossible to create a linear surface. |
4.For the given reference objects and direction, several variants of the resulting surface position are possible (see Figure). You can select the preferred way of plotting with the Previous result 
and Next result 
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5.To check a surface for self–intersections, please enable the Self-intersection check setting. If any self–intersections are detected, a corresponding message will appear on the screen. More details on surface self-intersection...
6.If necessary, set the name of the created surface and the properties of its display using the controls located in the Properties section. Managing the color and optical properties of objects...
7.To complete the operation, click Create an object 
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The created surface will be displayed in the graphic area; its icon .
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If plotting produces several linear surfaces instead on one (for example, if you have specified non-coherent faces as a base surface), then the process of changing surfaces set automatically starts after the plotting process. Select the surfaces that you want to keep. Details... Each of the resulting surfaces is a separate object. You can independently change their colors, hide them or move them into layers. But they will be registered as created by one feature, i.e. they will all change in case you edit the plotting feature. |
8.To complete operation of the command, click Finish 
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Tips
•You may use the curve selection (in item 1) marquee. If marquee catches several objects or object chains available for selection, the first of them is selected as a curve. In this case, the 'first' refers to the object constructed in the model earlier than the others.
If the marquee catches some solids, surfaces, or their faces, those will be selected as a base surface (see item 2).
See Also
Linear Surface on a Curve with Tangent to the Surface: Overview
