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Turbo Talk => Wish List => Topic started by: Régis Fraisse on December 24, 2019, 08:50:42 AM

Title: changing a line but not his length
Post by: Régis Fraisse on December 24, 2019, 08:50:42 AM
Imagine a rope. You can move it with your hands, you can have many geometry and the rope has always the same length.

My wish is to do that with a line on TurboCad.
Title: Re: changing a line but not his length
Post by: Alvin Gregorio on December 24, 2019, 09:53:08 AM
Imagine a rope. You can move it with your hands, you can have many geometry and the rope has always the same length.

My wish is to do that with a line on TurboCad.

Agreed.  I've long wished for this ability.  It would be very useful.
Title: Re: changing a line but not his length
Post by: John R on December 24, 2019, 12:05:34 PM
Have you tried using Constraints?

Use the "Auto Dimension" from the Constraints toolbar on a Line. Activate the Edit Tool and move an endpoint node to a new location. The line moves, but it retains its length. It will rotate unless both nodes are selected. From what I see, nothing is visible when moving.
Title: Re: changing a line but not his length
Post by: Henry Hubich on December 24, 2019, 06:17:54 PM
What am I missing here? I can select an existing Line and moved and/or rotate it like any other entity without changing its length.

Henry H
Title: Re: changing a line but not his length
Post by: Régis Fraisse on December 26, 2019, 01:47:43 AM
Have you tried using Constraints?

Use the "Auto Dimension" from the Constraints toolbar on a Line. Activate the Edit Tool and move an endpoint node to a new location. The line moves, but it retains its length. It will rotate unless both nodes are selected. From what I see, nothing is visible when moving.
OK, but it works only il I don't change the geometry of the line. My with is for example to put a node on the line, move this node and the total length doesn't change, and make a filet on the angle, etc. like with a rope.
Henry, maybe that answers your question.
Title: Re: changing a line but not his length
Post by: Henry Hubich on December 26, 2019, 08:45:50 AM
Have you tried using Constraints?

Use the "Auto Dimension" from the Constraints toolbar on a Line. Activate the Edit Tool and move an endpoint node to a new location. The line moves, but it retains its length. It will rotate unless both nodes are selected. From what I see, nothing is visible when moving.
OK, but it works only il I don't change the geometry of the line. My with is for example to put a node on the line, move this node and the total length doesn't change, and make a filet on the angle, etc. like with a rope.
Henry, maybe that answers your question.

Yes, it does. Thanks. And I agree that this would be a useful feature.

Henry H
Title: Re: changing a line but not his length
Post by: Jeffin90620 on January 04, 2020, 03:38:20 PM
My ... example to put a node on the line, move this node and the total length doesn't change, and make a filet on the angle, etc. like with a rope.

Then it's not a Line any more; it's a Polyline with Arc segments, but it does reveal a failing in the Polyline command's operation; when switching from a Line segment to an Arc segment, the Arc's start point is always tangent to its predecessor's segment, but a Line segment cannot be locked tangential to the Arc segment that precedes it.  For years, my preferred workaround has been to place Circles, then draw Lines tangent to the Circles, then V-snap a Polyline around the perimeter.

I suppose we could request a new command (let's call it Rope) where the length is specified first, followed by the origin point.  Then, as the cursor is moved around the screen, the rope is continuously re-drawn as if in Polyline mode, with each position click being incorporated into the resulting rope until the total length is used.  All segments, Line or Arc, would be tangential to the preceding segment.  If the last segment is desired to be an Arc, then the user can click and drag to adjust.


Jeff
Title: Re: changing a line but not his length
Post by: Henry Hubich on January 04, 2020, 05:32:18 PM
"...but a Line segment cannot be locked tangential to the Arc segment that precedes it."

Jeff, if you set "Relative angle" to zero, the line segment will be tangent to the preceding arc. But it's not locked (even if you click the "Lock" icon), and you have to reset it each time you draw a new line segment following an arc.

Henry H
Title: Re: changing a line but not his length
Post by: Jeffin90620 on January 04, 2020, 06:03:41 PM
if you set "Relative angle" to zero, the line segment will be tangent to the preceding arc. But it's not locked (even if you click the "Lock" icon)...

In my experiment, the Lock setting is obeyed, and remembered, too, so multiple additional line segments can be added (but it's reset if you switch to an Arc segment).


Jeff
Title: Re: changing a line but not his length
Post by: Régis Fraisse on January 05, 2020, 02:35:27 AM
Then it's not a Line any more; it's a Polyline with Arc segments
... and/or with curves (spline, bezier, sketch)
Title: Re: changing a line but not his length
Post by: Henry Hubich on January 05, 2020, 09:23:09 AM
if you set "Relative angle" to zero, the line segment will be tangent to the preceding arc. But it's not locked (even if you click the "Lock" icon)...

In my experiment, the Lock setting is obeyed, and remembered, too, so multiple additional line segments can be added (but it's reset if you switch to an Arc segment).

Jeff

Sorry I wasn't clear; that's what I meant.

Henry H