Skew surface

Is it possible to skew a surface in Rhino?

Here’s an example of what I mean:

skew

Note how the CVs are evenly and nicely redistributed during the operation too.

I used this all the time before, and it’s sorely missed.

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There is the ExtendSrf but performing the skew I have to project a curve and then use trim the surface. Not sure if there is anything similar to rhino

Taper , not so fun than this

“Scew” is a much needed tool in Rhino.

This is a good way to comfortably execute the “extend srf” command. The game of handles is not at all trivial, as many think, but it is more a comfort and, in my opinion, more functional.
To implement!

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I already proposed some ideas about future improvements in the manipulation of surfaces (including handles), and hopefully we could see some or all of them in Rhino 7 or Rhino 8. :slight_smile:

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Thank you all for the replies… it seems that the answer, for at least a couple of more years judging by Rhino’s development history, sadly then is “no”. :slight_smile:

(But I don’t even care about the handles, just a text option behind the command to skew that asks to click close to the end of an edge, and then use the same preview as with normal extend, would be enough for me.)

EDIT: The Alt shortcut to skew blend surfaces, by the way, is so obscure that I keep forgetting it! In that case, yes, handles would be way more intuitive… but perhaps they don’t want to stray too close to how Alias works, I don’t know?

try ShortPath, this would work well with splitting, since Rhino now has the option to shrink the surface, unfortunately that does not shrink it to its boarders here.

generally its also the method of how you work, the from @eobet described function above is fancy but is it really necessary? and for which exact situations do you need that?

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I have been looking for this one for ages. A legendary suggestion, Thanks!

VSR shape Control point modeling can replicate your example.

thanks - https://mcneel.myjetbrains.com/youtrack/issue/RH-54659

-Pascal

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One of the many indispensable commands in VSR/AD shape modeling.
The reason I keep using Rhino5 alongside version 6.

Plus one on the implementation of this, very helpful.

Hi all - If you are feeling adventurous, see how this prototype works for skewing.

ExtendSurfaceEdge.rhp (21 KB)

There’s probably tons wrong with it but it seems to work for at least simple and non-rational surfaces.

Currently, the command keeps running until Enter stops it - I am wary of commands that don’t just get out of the way but the context here seemed to me one where you’d ‘fiddle’ with it until you like the result. It is easy to turn that off.

You get one level of Undo and there is not any distance feedback, but I think that is ‘just typing’.

You’ll need to unblock the rhp and then drag and drop to load it up. The command is

ExtendEdge

I’d be curious to hear, if you are brave enough to test, whether it is on the right track… in real life.

It is probably not hard to add a center control to move the entire edge like ExtendSrf as well as allow extending individual control point rows - I am not sure if that is a good idea.

@eobet, @StefGyft, @Rhino_Bulgaria, @TomTom, @Stratosfear, @encephalon , @norbert_geelen , @Mark_Landsaat

-Pascal

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That’s a fantastic job, Pascal! This tool will definitely help in many cases where some surface edge must be moved closer to another one in a gradual fashion, just like it’s shown on your GIF image. Extending individual rows of control points is also something that I needed in the past. It was quite slow to use Move UVN on each control point with different distance to make it happen manually.

I test the “Extend surface edge” command and it works quite well! :slight_smile: Of course, in some situations with moving the edge too far away it produced strange shapes, but that’s understandable. It’s a great way to increase the width of a surface in both ways, too. I tested in on a propeller and it was easy to make it’s outer edge twice as wide. Hopefully that there is a chance to add an option to extend by user-set distance, simultaneous extending of both sides of the edge, and greater number of internal Undo/Redo states. Even it its current form it’s a very useful tool. :slight_smile:

Hi Pascal, thanks for putting this together. This looks quite useful to me. I will give you more updated information once I have had the opportunity to test this. I have a carbon bicycle fork project coming up and I believe there will be an opportunity to test this command in the real world for that. I will keep you updated.

Thanks,
Mark.

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Mark, I made a version that attaches the surface to a mesh - if you’re reverse engineering from a scan for the carbon part, it might be helpful. Shout if you want to try, I think it works OK.

-Pascal

@pascal. No it’s not reverse engineering, new design. So no scanned mesh involved. I like to use sweep1 in some cases to create a simple overbuild surface. This technique allows me to deform the resulting “square” and reshape it. I like this technique because it maintains the “character” of the shape. At any rate, look forward to trying this.

I played with this for a few minutes and it’s quite promising. Would be great if we could a point to move from and point to move to option, but even as it seems already useful. Will have to try on a project at a later time.