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pydim.create_radial_dimension

fabian-flassig edited this page Jul 31, 2026 · 1 revision

Creates a radius, diameter, center or arc-length dimension from three points on an arc.

Similar to the Dimensions -> Radius / Diameter / Center / Arc length functions in the PYTHA user interface. The dimension is anchored to existing part points and follows the parts when they are modified.

pydim.create_radial_dimension(point1, point2, point3 [,options])
Parameter Type Description
point1 {{x,y,z} [,element]} Start of the arc: the coordinate at index 1 and, optionally, a part or group element handle at index 2. The coordinate must coincide with an existing point; reference points take priority over part points (see pydim).
point2 {{x,y,z} [,element]} A point on the arc between start and end, same form as point1.
point3 {{x,y,z} [,element]} End of the arc, same form as point1.
options {...} Optional: a table that may contain the following options:
options.type string Dimension type: "radius" (default), "diameter", "center" or "arc_length".
options.view string The view in which the dimension is displayed: "xy", "-xy", "xz", "-xz", "yz", "-yz" or "axo" (default "axo").
options.angle number Angular position of the dimension around the arc in degrees, relative to the direction of point2 (default 0).
options.length number Length of the dimension line as a factor of the radius: 1 ends exactly on the arc, larger values place arrow and text outside (default 1).
options.style_file path handle A dimension style file (as saved from the dimension attributes dialog) loaded as the base style.
options.style {...} Individual style settings applied on top; the keys are listed at pydim.create_linear_dimension.

Return value

Type Description
element_handle An element handle of type "dimension" for the new dimension — or nil if one of the coordinates does not match a part point or the three points are collinear.

Example:

Radius of a cylinder base circle (three points on the circle at 0°, 90° and 180°):

local cyl = pytha.create_cylinder(350, 150, {1000, 200, 0}, {segments = 24})

pydim.create_radial_dimension(
    {{1150, 200, 0}, cyl},
    {{1000, 350, 0}, cyl},
    {{850, 200, 0}, cyl},
    {type = "radius", view = "xy", angle = 45})

Remarks:

  • The three points must lie on the arc and must not be collinear.
  • "center" marks the center of the circle; options.angle has no effect on it.
  • Style values that are not specified are taken from the current default dimension style.
  • Dimensions are created in the model, not on plot sheets.

Version Support:

Minimum PYTHA Version: V27

See also:

pydim, create_linear_dimension, element handles, Path Handles, delete_element

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