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Wrapping a sketch onto a surface

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Answers

  • john_mcclaryjohn_mcclary Member, Developers Posts: 1,920 PRO
    @Jake_Rosenfeld
    thanks for the heads up
  • dave_cowdendave_cowden Member, Developers Posts: 445 ✭✭✭
    @MBartlett21 ; wow thats cool, thanks for the heads up!
  • MBartlett21MBartlett21 Member Posts: 1,580 EDU
    @MBartlett21
    @john_mcclary

    I apologize for the inconvenience, opRoll should have been released with an @internal tag.  Please feel free to play around, but the behavior may experience some changes over the next few releases, and there is a small chance that geometry created by this feature will change slightly from one release to the next.  Hold tight to use this in production work.
    @Jake_Rosenfeld
    Should this also go for the Hem feature (it does not have an @internal flag and it also uses opRoll).
    MB - I make FeatureScripts: view FS (My FS's have "Official" beside them)
  • hans_haenleinhans_haenlein Member Posts: 9 PRO
    This has become a long and interesting discussion thread, but my original request has not yet been addressed. I'm after a more general mapping function that maps any 2D curve or curves onto any 3D surface, not just a cylinder.
    My understanding is that all surfaces, even those that topologically knit together to form a solid, are 4 sided parametric entities with whatever underlying math (most likely non-uniform rational b-spline or bezier). Note that sometimes one or two edges can collapses to a point, or a vanishingly small edge (like the poles of a sphere).
    Two more important aspects (of surfaces) are the U and V parameters. These are values on the surface ranging from 0 to 1, used in the mathematical definition of the surface and for defining paths on the surface: for example, a trimmed boundary edge. Note that they are not proportionally spaced along the surface. A curve of constant U or constant V is known as an isoparametric curve, or U (V) line. In CAD systems, surfaces are often displayed with their poles of constant U or constant V values connected together by lines; these are known as control polygons. (straight from Wikipedia)
    This means that every point on every surface can be defined by a single (u,v) parameter, where 0<=u<=1 and 0<=v<=1.
    My request is that any 2 dimensional curve drawn in the same plane (the x,y plane for instance) as a bounding rectangular (or square)  can be mapped onto any surface, where one corner of the bounding rectangle or square maps to u=0, v=0, and its diagonal opposite corner maps to u=1, v=1.
    What this mapping means in real life depends on how you set up the curve(s) on the flat plane, and how you set up the mapping surface. This is easy to imagine and set up for an extruded surface, gets a little more strange, but still useful, for a more complex surface. It doesn't have to be a 1:1 scale in either axis, but you can set it up to be that.
  • Jake_RosenfeldJake_Rosenfeld Moderator, Onshape Employees, Developers Posts: 1,295
    edited January 25
    @hans_haenlein

    This is the goal of the new opRoll interface.  After cylinders we will be building over time to support other developable surfaces.  We are also working on a built-in feature so that users do not need to implement a custom feature on top of opRoll.

    @MBartlett21
    Because of the planned change to opRoll, yes, a sheetMetalHem may go from failing to passing in an unexpected way. We've done some categorization of the opRoll change, though, and it is not likely to cause major problems.
    Jake Rosenfeld - Modeling Team
  • hans_haenleinhans_haenlein Member Posts: 9 PRO
    Thanks Lana - this sounds like it would do it. Now I just need to write the Feature Script...
  • chris_bottinochris_bottino Member Posts: 8 ✭✭
    @hans_haenlein

    This is the goal of the new opRoll interface.  After cylinders we will be building over time to support other developable surfaces.  We are also working on a built-in feature so that users do not need to implement a custom feature on top of opRoll.

    @MBartlett21
    Because of the planned change to opRoll, yes, a sheetMetalHem may go from failing to passing in an unexpected way. We've done some categorization of the opRoll change, though, and it is not likely to cause major problems.
    Hi Jake - so is there an unstable "beta" way to use/test opRoll now to project a sketch onto a non circular surface?  Thanks
  • Jake_RosenfeldJake_Rosenfeld Moderator, Onshape Employees, Developers Posts: 1,295
    @chris_bottino I can't find it right now, but in another thread we mentioned that opRoll is now stable and fine to use; but we have not yet released a feature for its usage (though I bet that @konstantin_shiriazdanov and @MBartlett21 have been playing around with it).  Although the interface is now stable, it does only support cylinder wrapping.
    Jake Rosenfeld - Modeling Team
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