MicroStation CONNECT Edition Help

Loft Surface

Used to construct a B-spline parametric surface that is transformed between section elements (lines, line strings, arcs, ellipses, complex chains, complex shapes, B-spline curves, or the edges of a surface). Multiple sections can be selected with <ctrl+data points> and should be selected in the order that the surface is to be created.

All section elements must be in the same direction to avoid the resulting surface from being “twisted.” As you select each element, arrows display indicating each element's direction. To reverse the direction of the section, click the arrow. On closed sections, to relocate the start point click the sphere at the base of the direction arrow and drag it to the required position.

You can access this tool from the following:

  • Ribbon: Modeling > Surfaces > Create Surfaces > Loft > Loft
  • Toolbox: Create Freeform Surfaces
Loft by Sections icon

Creates a surface between the selected section curves. The section curve can be the edge of a surface or solid.
Loft by Sections with Guide Wires icon

Creates a surface using both the selected section curves, and selected Guide Wires that control the shape of the surface between the section curves. The Guide Wires can be curves or the edge of a surface or a solid.
Force Start Point at Selection Point If on, the start point for the section curves is defined by the identification point such that:
  • for a closed curve, the start point is at the snap point.
  • for an open curve, the start point is at the end nearest to the snap point.
Close Loft If on, a closed surface is constructed in which the first section curve is used as the last section curve.
Segmented Loft (Loft by Sections only)

If on, surfaces are created linearly between each section curve, with no smoothing.

If off, smoothing is applied to the generated surface.

Profile Sets the behavior of the profile after the feature is created.
  • Hide - The profile is associated with the feature to allow for later modification, but is not visible. To use or modify the profile again, you will need to use Show Input Element command from the reset pop-up menu or the Show Input Element tool.
  • Show - The profile is associated with the feature to allow for later modification and is visible. This allows you to quickly reuse the same profile in another 3D operation. Modifying the profile will affect both operations.
  • Copy and Hide - Similar to Hide; except that a copy of the profile is made first, leaving the original profile unassociated. This allows you to quickly reuse the same profile in another 3D operation that you do not wish to be associated with the previous feature.
Parametric If on, a parametric surface is created with the profile as an input element. The profile can be handled like other feature inputs, allowing you to show /hide, apply constraints, replace etc.