Need help to write some documentation about U V surfaces.

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onekk
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Re: Need help to write some documentation about U V surfaces.

Post by onekk »

chrisb wrote: Wed Jun 22, 2022 8:20 pm I would be happy to have a layman's view on it.
Here a little try, not so much text, and probably there are some mistakes and errors.

Introductory part is maybe the most difficult, as when trying to explain concepts, it is easy to make big mistakes:

The text is somewhat "dirty" as there are some remnants of the whole document framework, but better 4 pages than 70 as the full document will have been.
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TIA and Regards

Carlo D.
GitHub page: https://github.com/onekk/freecad-doc.
- In deep articles on FreeCAD.
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edwilliams16
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Re: Need help to write some documentation about U V surfaces.

Post by edwilliams16 »

Here's an illustration of the u,v coordinates on a segment of a sphere and on a cylinder, using the Curves workbench|Isocurves tool. A u-isocurve is a curve of constant u value , on only which v varies. The isocurves form a grid which is the u, v coordinate system.

For the sphere, the u,v coordinates ate longitude and latitude (in radians). On the cylinder, they are as you described.
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onekk
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Re: Need help to write some documentation about U V surfaces.

Post by onekk »

edwilliams16 wrote: Wed Jul 06, 2022 4:10 am Here's an illustration of the u,v
...
Thanks @edwilliams16 , I have to study some more, probably I have to search some documentation about isocurves. :-D

Did you read the text?

It is readable or you suggest some modifications?

TIA and Regards

Carlo D.
GitHub page: https://github.com/onekk/freecad-doc.
- In deep articles on FreeCAD.
- Learning how to model with scripting.
- Various other stuffs.

Blog: https://okkmkblog.wordpress.com/
edwilliams16
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Re: Need help to write some documentation about U V surfaces.

Post by edwilliams16 »

onekk wrote: Wed Jul 06, 2022 2:57 pm
Did you read the text?

It is readable or you suggest some modifications?

I read it. It appears to be a good intruduction - but I'm wondering what you intend to cover in the scripting part. I would guess toShape() mapping a 2D curve onto a 3D surface, but what else? distToShape()?
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onekk
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Re: Need help to write some documentation about U V surfaces.

Post by onekk »

It seems that the UV surfaces are not very covered by documentation.

I think it could be very useful to submit some code about mapping things on surfaces or obtain paths to make thread and similar things.

distToShape() in my mind was not related, but I'm open for suggestions and some example code.

Probably also some code about determining UV coordinates to place Character like shapes on curved surfaces (At least for me a part for some macro around the entire mechanism has some "dark spots".

Ultimate goal is to cover Scripting and some "not basic" techniques. UV Surfaces (and UV Coordinates) seem to be a good starting point.
edwilliams16 wrote: Wed Jul 06, 2022 4:10 am ...

Edit:

I have a problem described here:
https://forum.freecadweb.org/viewtopic.php?f=22&t=70078

End Edit

TIA and Regards.

Carlo D.
GitHub page: https://github.com/onekk/freecad-doc.
- In deep articles on FreeCAD.
- Learning how to model with scripting.
- Various other stuffs.

Blog: https://okkmkblog.wordpress.com/
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