(novice) Just trying to loft two triangles into a tetrahedron...

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FBXL5
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by FBXL5 »

papyblaise wrote: Wed Nov 16, 2022 9:08 am you can also make a loft between a point (top of the pyramid) and the triangle
It was my first thought, too. But then I supplied the wrong picture... :roll:

It is good to know that in many cases there is more than one way to achieve a goal.
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papyblaise
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by papyblaise »

all roads lead to rum: a straight one to go and a winding one to come back
AidanofVT
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by AidanofVT »

FBXL5 wrote: Wed Nov 16, 2022 8:54 am It would be nice to have a hint that the selected element is not the whole sketch but only one point.
papyblaise wrote: Wed Nov 16, 2022 9:08 am you can also make a loft between a point (top of the pyramid) and the triangle
I understand. I actually was trying to do exactly this; I think what I'm missing is how exactly you guys are selecting points/lines out of sketches. Are you using the python console or something?

I wrote several drafts of a paragraph here outlining all the ways I've tried to replicate what you're doing, but allas, I think it's better to just say that I'm unable to select individual lines/points, and even when I find partial workarounds, the tools fail with various errors.

I am looking at your examples. I see it's possible. Heck, I even made it work myself once, with that polyhedron example. Perhaps one of you could record a video, so I can see exactly what you're doing?
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papyblaise
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by papyblaise »

I am unable to video
I forgot an important info: the point to draw in the sketcher is not a valid point (in red) but a construction point (in blue) it must be transformed with the blue square / red square button
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FBXL5
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by FBXL5 »

I was born and raised in the pre-video era and still have no clue how to record one. :mrgreen:

Whole sketches should be selected in the tree view, single elements can only be selected in the 3D window.
Selecting points on a hi res screen is hard to do if you are still running default settings, but you can increase their size in the preferences: Preferences -> Part/Part Design -> Shape appearance -> Vertex size

Edit: That was wrong :roll: the sketcher point size do not depend on this preference, but can be set in the sketch's properties; under the view tab look for Point Size.

I rarely use Loft or Pipe tools in FC (for other tasks than compiling examples) and could only cite the wiki pages for the workflow. :?
Last edited by FBXL5 on Thu Nov 17, 2022 7:59 am, edited 2 times in total.
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FBXL5
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by FBXL5 »

papyblaise wrote: Thu Nov 17, 2022 7:26 am I am unable to video
I forgot an important info: the point to draw in the sketcher is not a valid point (in red) but a construction point (in blue) it must be transformed with the blue square / red square button
I've heard/read that before, but I haven't set a sketcher point into construction mode yet and am still able to select it, for the given example.
Tried again and observed that sketcher points outside editing mode are always selectable but hard to be seen, but their size can be altered in the sketch's properties.

Edit: If you use separate Point elements they have to be toggled from red to white (or green if fully constrained) with mentioned Toggle construction geometry button to be visible outside edit mode.
But start and end points of lines are always visible outside edit mode, but you need a magnifier to notice if you don' change the size. And you can't change their mode, they will stay red.
AidanofVT
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by AidanofVT »

Based on what you say, and what I read on the FreeCAD wiki about Sketcher ToggleConstruction, I understand that I want points/lines that are red/white, NOT blue. I believe this is what I had before. Nevertheless, see attached proof that my lines are all real, and my shapes are fully constrained:

Image
Image

I can't seem to get my vertices larger than 9pt; you can see that the 'enlarge' arrow is greyed-out. Even after lowering line thickness to 3pt, those vertices still are practically invisible. Here's what my settings window looks like:

Image

When I try to use the additive pipe tool, some lines and vertices are selectable, but not the ones I need. It seems as though I can always select points that are on convex edges or flat surfaces, but never ones that are in concave edges. So, as shown, I can select this line on the flat surface, but not the overlapping line which is part of the desired sketch:

Image

Find attached the version of this file that these screenshots were taken from.
Attachments
spaceship.FCStd
(48.34 KiB) Downloaded 7 times
Bance
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by Bance »

Use the space bar to toggle the visibility of the solid (and any superfluous sketches)...
Attachments
Screenshot_2022-11-25_09-01-03.png
Screenshot_2022-11-25_09-01-03.png (151.83 KiB) Viewed 439 times
AidanofVT
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by AidanofVT »

Trying to replicate your image (by clicking space with the "Chamfer" step selected, while in the loft operation) results in this:

Image

This was likely because I still can't select a point out of Sketch004. Going the other way, from 004 to 002, I actually was successful, maybe because I was able to select the point. So thanks, Bance.

I wasn't able to get additive pipe to work in either direction.

I also notice, as you can see in the above image, that the line thicknesses in 002 and 004 are quite different, implying that there's something different about them. Yet, as you can see in my previous post, they seem to be qualitatively the same. Any insights?
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Re: (novice) Just trying to loft two triangles into a tetrahedron...

Post by chrisb »

AidanofVT wrote: Sat Nov 26, 2022 5:43 am Any insights?
Sure not without the file.

For better selectability you can increase the "Pick radius" in Preferences->Display.
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