Sketcher CreateEllipseByCenter
Menu location |
---|
Sketch → Sketcher geometries → Create ellipse by center |
Workbenches |
Sketcher |
Default shortcut |
None |
Introduced in version |
0.15 |
See also |
Sketcher Ellipse by 3 Points, Sketcher Circle, Sketcher Arc of Ellipse |
Contents |
Description
This tool draws an ellipse by picking three points: the center, the end of major radius, the minor radius. When starting the tool, the mouse pointer changes to a white cross with a red ellipse icon. Besides are coordinates shown in real time.
How to use
- Invoke the command by clicking a toolbar button, picking the menu item, or by using keyboard shortcut (needs to be assigned first in Interface Customization).
- First click in 3D view sets ellipse center. Second click sets the first radius and orientation of the ellipse. Third click sets the other radius (the distance from the line defined by first two clicks is the second radius).
- After the third click, the ellipse is created, together with a set of construction geometry aligned to it (major diameter, minor diameter, two foci). The construction geometry can be manually deleted if not needed, and recreated later. See Internal Alignment Constraint and Sketcher Show Hide Internal Geometry.
- Pressing ESC or clicking the right mouse button cancels the function.
Peculiarities
- Major and minor axes of ellipses are strict and cannot be swapped by resizing the ellipse. This is a consequence of the solver parametrization used (center (x,y), focus1 (x,y) and minor radius length (b)) and the same strict behavior of OpenCascade. The ellipse must be rotated to swap the axes.
- Ellipse can function as a circle when its major and minor diameter lines are deleted, and one of the foci is constrained to coincide with the center. But radius constraint won't work on such a circle.
- Moving the ellipse by edge is the same as moving ellipse's center.
Sketcher
- The tools: New sketch, Edit sketch, Leave sketch, View sketch, View section, Map sketch to face, Reorient sketch, Validate sketch, Merge sketches, Mirror sketch
- Sketcher geometries: Point, Line by 2 point, Create an arc, Arc, Arc by 3 Point, Create a circle, Circle, Circle by 3 Point, Create a conic, Ellipse by center, Ellipse by 3 points, Arc of ellipse, Arc of hyperbola, Arc of parabola, Create a B-spline, Create B-spline, Create periodic B-pline, Polyline (multiple-point line), Rectangle, Create regular polygon, Triangle, Square, Pentagon, Hexagon, Heptagon, Octagon, Create Regular Polygon, Slot, Fillet, Trimming, Extend, External Geometry, CarbonCopy, Construction Mode
- Sketcher constraints
- Geometric constraints Coincident, Point On Object, Vertical, Horizontal, Parallel, Perpendicular, Tangent, Equal Length, Symmetric, Constrain Block
- Dimensional constraints Lock, Horizontal Distance, Vertical Distance, Distance, Radius, Internal Angle, Snell's Law, Internal Alignment, Toggle reference/driving constraint,
- Sketcher tools Select solver DOFs, Close Shape, Connect Edges, Select Constraints, Select Origin, Select Vertical Axis, Select Horizontal Axis, Select Redundant Constraints, Select Conflicting Constraints, Select Elements Associated with constraints, Show/Hide internal geometry, Symmetry, Clone, Copy, Move, Rectangular Array, Delete All Geometry, Delete All Constraints
- Sketcher B-spline tools Show/Hide B-spline degree, Show/Hide B-spline control polygon, Show/Hide B-spline curvature comb, Show/Hide B-spline knot multiplicity, Convert Geometry to B-spline, Increase degree, Increase knot multiplicity, Decrease knot multiplicity
- Sketcher virtual space Switch Virtual Space
User documentation
- Installation: Unix, Windows, Mac; Getting started
- Basics: About FreeCAD, Workbenches, Preferences, Document structure, Interface Customization, Properties, Mouse Model; Tutorials
- Workbenches: Arch, Draft, FEM, Image, Inspection, Mesh, OpenSCAD, Part, PartDesign, Path, Plot, Points, Raytracing, Reverse Engineering, Robot, Ship, Sketcher, Spreadsheet, Start, Surface workbench, TechDraw, Test Framework, Web
- Scripting: Introduction to Python, FreeCAD scripting tutorial, FreeCAD Scripting Basics, How to install macros, Gui Command, Units Modules: Builtin modules, Workbench creation, Installing more workbenches Meshes: Mesh Scripting, Mesh Module Parts: The Part Module, Topological data scripting, PythonOCC, Mesh to Part Coin scenegraph: The Coin/Inventor scenegraph, Pivy Qt interface: PySide, Using the FreeCAD GUI, Dialog creation Parametric objects: Scripted objects Other: Code snippets, Line drawing function, Embedding FreeCAD, FreeCAD vector math library, Power users hub, Python, Macros, FreeCAD Scripting Basics, Topological data scripting