Sketcher B-сплайн
Sketcher Нарисовать B-сплайн |
Системное название |
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Sketcher CreateBSpline |
Расположение в меню |
Sketch → Геометрия эскизов → Нарисовать B-сплайн |
Верстаки |
Sketcher |
Быстрые клавиши |
Нет |
Представлено в версии |
0.17 |
См. также |
Sketcher Нарисовать периодический B-сплайн |
Описание
This tool traces an open B-spline curve from its control points. Этот инструмент строит незамкнутую кривую B-сплайна по его контрольным точкам.
Кривая B-сплайна построена по 4 точкам (белого цвета). На рисунке изображены контрольные многоугольники зеленым цветом (прямые, соединяющие красные точки), синие круги с весами и гребень кривизны зеленым цветом. Цифра (3) в центре относится к степени B-сплайна, а цифры (4) на концах кривой относятся к множественности их узлов.
Как использовать
- Press the Create B-spline button.
- Create a series of points by clicking in the 3D view. While the command is active, the created points are connected with straight lines, and a construction circle is created centred on each point.
- Right-click to terminate the input and generate the curve.
- Depending on preferences, the tool may remain active to trace a new curve. Right-click again to exit the command.
- It is possible to define the weight of the control points by changing the radii of the weight circles. The equality constraints on the circles need to be deleted first. The radius constraint is arbitrary, the weight of the control points will be defined by the relative radii of the circles. It works similar to gravity: the bigger a circle is in relation to the others, the more the curve will be attracted to the control point.
- The visibility of the control polygon, the curvature comb, the degree and the knot multiplicity can be toggled on/off from the B-spline tools toolbar.
- Check out the other tools in the B-spline tools toolbar for more B-spline editing tools.
Limitations
- Many types of constraints are not supported at this time. Only the B-spline's control point and end points can be constrained.
- Trimming and extend tools are not supported.
- The shape of a B-spline curve can only be edited by dragging one of the control points. The knots lying on the curve cannot be selected.
Sketcher
- General: Create sketch, Edit sketch, Attach sketch, Reorient sketch, Validate sketch, Merge sketches, Mirror sketch, Leave sketch, View sketch, View section, Toggle grid, Toggle snap, Configure rendering order, Stop operation
- Sketcher geometries: Point, Polyline, Line, Arc, Arc by 3 points, Arc of ellipse, Arc of hyperbola, Arc of parabola, Circle, Circle by 3 points, Ellipse, Ellipse by 3 points, Rectangle, Centered rectangle, Rounded rectangle, Triangle, Square, Pentagon, Hexagon, Heptagon, Octagon, Regular polygon, Slot, Arc slot, B-spline by control points, Periodic B-spline by control points, B-spline by knots, Periodic B-spline by knots, Toggle construction geometry
- Sketcher constraints:
- Dimensional constraints: Dimension, Horizontal distance, Vertical distance, Distance, Auto radius/diameter, Radius, Diameter, Angle, Lock
- Geometric constraints: Coincident (unified), Coincident, Point on object, Horizontal/vertical, Horizontal, Vertical, Parallel, Perpendicular, Tangent or collinear, Equal, Symmetric, Block
- Other constraints: Refraction (Snell's law)
- Constraint tools: Toggle driving/reference constraint, Activate/deactivate constraint
- Sketcher tools: Fillet, Chamfer, Trim, Split, Extend, External geometry, Carbon copy, Select origin, Select horizontal axis, Select vertical axis, Array transform, Polar transform, Scale transform, Offset geometry, Symmetry, Remove axes alignment, Delete all geometry, Delete all constraints
- Sketcher B-spline tools: Convert geometry to B-spline, Increase B-spline degree, Decrease B-spline degree, Increase knot multiplicity, Decrease knot multiplicity, Insert knot, Join curves
- Sketcher visual: Select unconstrained DoF, Select associated constraints, Select associated geometry, Select redundant constraints, Select conflicting constraints, Show/hide circular helper for arcs, Show/hide B-spline degree, Show/hide B-spline control polygon, Show/hide B-spline curvature comb, Show/hide B-spline knot multiplicity, Show/hide B-spline control point weight, Show/hide internal geometry, Switch virtual space
- Additional: Sketcher Dialog, Preferences, Sketcher scripting
User documentation
- Getting started
- Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
- Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate
- Help: Tutorials, Video tutorials
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