Guided Loft is a combination of the Sweep and Loft commands without the need for multiple workplanes. The sweep part of the functionality moves one or more profiles along a smooth spine and automatically creates intermediate help profiles which are lofted to create surfaces. To read more about Sweep and Loft, see
Sweep a part and
Lofted freeform parts. Not all directions and limitations for Sweep and Loft apply to Guided Loft.
To create and place intermediate help profiles onto a spine, the following conditions must be fulfilled:
• The profiles must be planar edge chains.
• The plane in which the edges of the profile lie has to be orthogonal to the spine.
If these conditions are not met, some options in the Guided Loft menu are disabled.
The spine, profiles, and birails can be 2D or 3D edges. For best results, use planar profiles that are orthogonal to the spine. Control the shape of the generated surfaces with Variation Options.
Tips when working with Guided Loft
• Keep the number of profiles low. The number of profiles is directly proportional to the "price" of the surface. The more profiles, the more expensive the price of the surface.
• The option Show help profiles will show how expensive the surface will become. Use Show help profiles when working with birails since birails make the surface expensive.
• Use the simplest curves possible. The best choice are splines created by Creo Elements/Direct Modeling. Intersection curves are expensive because of their dependence on part resolutions.
• Reduce the part resolution to 1e-3 or 1e-4 mm, or, if an interpolation is not necessary, use the Variation Options to create special shapes. The goal is to create a surface that interpolates the birail curves with the current part resolution (or the default resolution if an empty part is given).
• Variation Options let you create complex shapes from simple inputs by scaling, rotating, and changing weights of the profiles to control how they are blended, and by adding variable offsets to profile curves.
To create a guided loft,
1. Activate the Surfacing module.
a. Click File > Modules. The Modules dialog box opens.
b. On the Modules pane, click Surfacing under Licensed.
2. Click Surfacing and then, in the Advanced Surfacing group, click Guided Loft. The Guided Loft and Select dialog boxes open.
3. Name the part.
4. Click the curve to be the Spine. The spine will be orange.
5. Select the Profile Edges. Use the Select tool to select multiple curves and profiles. The profile(s) will be blue.
After selecting a spine and profile, a blue point is shown on the spine. This is the attachment point of the profile to the spine, which is an intersection of the profile's plane and the spine. If the profile is at the end of the spine, make sure the spine is long enough to intersect the profile's plane. When working with a non-planar profile, there is no plane to intersect the spine and the system calculates a suitable attachment point.
6. Specify any of the following: Continuity, Birails, Scaling, Variation Options, or Matchlines.
7. Click Preview to see the guided loft.
8. Click to complete the operation.
Other menu options
• Other Side: Under Spine. This option is active if the system can create only a part of the surface. For example when Scalar: Linear is chosen, only part of the surface will be created. Click Other Side to switch the start and end points of the surface. The start and end points include an attachment point and one end of the spine.
• Reverse: Under Profile Edges. Use this option to fix a self-intersecting surface that has a profile with an orientation different from the other profile orientations. Click Reverse and click any edge of the profile to reverse that profile.
• Split at: Under Spine when working with a single profile and a spine that is more than one edge. Under Profile Edges when working with multiple profiles. Use this option to split the generated surface at the vertices of the spine or at the profiles. In either case, more than one surface is created.
• Continuity: Use a continuity option with the spine or birails to create a surface that is tangentially or curvature continuously connected to adjacent faces.
• Orientation: Use an orientation option to influence how a profile is turned along a spine.
• Blending: Use the blending options to control how multiple profiles will be blended and to influence the shape of the surface.
• Show help profiles: Use this option to show where the intermediate help profiles have been created and how expensive the surface will become. The more help profiles there are, the more expensive the surface will become. Birails make the surface expensive.
Normally, enough help profiles are calculated to ensure that the guided loft surface becomes the expected shape. If the shape is not what you want, you can add help profiles by specifying a value for the Maximum Distance field. The maximum distance is the distance between two adjacent help profiles. Additional help profiles will be added when the distance between two adjacent help profiles is larger than the maximum distance specified.
• Flip Faces: Use this option to change the view of the face. This is important to Surface Analysis, which uses face normals for analysis.
• Preview: Use Preview to see the result of the guided loft.
• Check: Use Check to analyze newly created surfaces. The check is done when is pushed. For better performance, do not use Check with Preview. If Check is not used, corrupt surfaces may be produced.
• Surface Analysis: Use the Surface Analysis tool to analyze the quality of the surfaces.
Guided Loft. The Guided Loft and Select dialog boxes open.
to complete the operation.