Surface building commands

I have question about surface building commands in rhino …when I can build a surface by more than one method(loft/patch/2railsweep etc.) which one should i choose ? in other words i need to know for what specific purpose each of this commands were included in rhino

if you hit F1 while in the command it pulls up a detailed help description of the command.

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my question wasn’t about how to use surface building commands ! i need to know which surface building command is preferable in which scenario

That one is pretty much impossible to answer. If you come up with a list of all possible scenarios, perhaps …

A lot is just user preference, combined with user experience. There are so many ways of achieving the same result… No one is necessarily more right than the other.

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Reasons for using a particular command can include"

  • Available input curves, etc.
  • Accuracy and degree of matching input curves/edges
  • Shape of results

Loft uses one set of “section” curves. No control, besides options, of the shape between the curves. Options for the number of control points.

EdgeSrf uses 2, 3 or 4 edge curves and will exactly match the input curves but may have multi-knots. All edge curves contribute “equally” to the shape. No control of slope or curvature at the edges.

Sweep1 uses 1 rail curve and a set of section curves. The surface is created by blending the section curves along the rail. Multiple options for how the blending is done and how the rail curve affects the shape. Also options for the number of control points.

Sweep2 uses 2 rail curves and a set of section curves. The surface is created by blending the section curves between the rails. Several options for how the blending is done. Options for degree of matching with surfaces with edges used as rail curve.

NetworkSrf uses a network of curves, and creates a surface with specified accuracy to those curves. Any kinks, etc are smoothed. Options for matching tangency and curvature of adjacent surfaces.

Patch creates a surface which is a “best fit” to the input. There are multiple ways to use Patch. Patch is best used when other commands won’t work.

Choice of which command to use depends on the available input information, required matching of input information, and desired shape.

Read the Help sections on each command including the information about the options.

Experiment. Spend some time creating sets of curves, and then create surfaces from the curves using different options with a single command, and using different commands. Compare the results. One of the advantages of CAD is the ease of trying something, then backing up and trying something else, without any cost for materials.


“undo” is such a useful command! Probably most frequently used, too. :grinning: