Moving endpoint of line without changing the length of the line

I have a room with five walls. Two of them are at odd angles. However, they are of a fixed length, I cannot change the length of the walls.

What I want to do is to use SketchUp and draw the room. Three of the walls are easy. It is the two angled walls that are being a problem. What I want to do is move those two walls, in SketchUp, so that the endpoints meet. I want to do this without changing the length of the lines (one is 80 mm, reflecting 8m and one is 3.6 mm, reflecting 3.6 meters).

I have looked. Al it the hits I have found are about changing the length of the line, that is easy. What I want is to move the endpoint without changing the length of the line, or rescaling the entire building, yes, I found how to do that too.

I expect you should be able to move the walls into place but it would be much easier to help you if you share the SKP file.

I have no doubt that it would be simpler. However, I can not find where sketchup is storing the files. If it helps any, I am using the online, free, version.

I am trying to find instructions for doing this now.

Click on the file folder icon and download the file to your computer so you can upload it here.

And complete your profile with the SketchUp version. This information helps us help you.

It is better to make your model to full scale so if your wall is 8 m long in reality, make it 8m long in your SketchUp model too. You can apply scaling when you print or export your model. The SketchUp model space has no limits except those imposed by the display system, but you can safely model things that are about a kilometer across.

1 Like

Here is the model
Basic B-111.skp (167.9 KB)

Edited to remove comments, I can’t find a delete button.

The idea is to create a scale 3d model of the school I teach at (US Middle School, grades 6-8). I teach Robotics and Photoshop.

In Robotics we use the 3d printer to make odd parts that don’t exist. Normally we (either me or the students) use Tinkercad for those projects.

The administration decided that building a model of the school would be a great idea. Based on limited knowledge of Sketchup (yes, the “House” walkthrough) I thought it would be a better tool for what I want to do. I am sure that it probably is a better tool, it comes down to how to make it do what I want.

Oh, and the measurements I have are actually a bit off, the students measured the inside of the room, not taking wall thickness into full account. Not all of the walls are shared with other rooms. So, really todays experiments were just me trying to see how well it would work.

To ask, can you point me to a you-Tube, or something, that shows how to use the pie tool to join line segments? All of the ones I found were about drawing curves.

. . sorry about seeming so grumpy,

@DaveR, maybe nitpicking (depends on what accuracy one needs). The challenge (for obtaining exact matching lengths with only the native tools) still remains.

In your construction both new lengths are different from the original lengths due to segmented pies.

If you carefully position the end (red cross!) of the second pie on the first pie, the second new length is correct, same as the original. But still, the first new length isn’t due to the first pie being seen as segmented.

So the challenge remains to get them both exactly right.

3 Likes

I don’t see that as nitpicking. Correct length is simply correct length.
Finding the intersection of arcs is fundamental geometry, since Euclid.

SketchUp’s pathetic inability to find true arc intersections has dogged users since day one.
@jbacus @SketchupDoug How do you propose to teach children the fundamentals of geometric construction when the tool you push in front of them cannot perform elemental geometry?

8 Likes

Hello Robert,

As far as i know, it is not possible to do this with the online free version of Sketchup, nor with the desktop version with the use of the native SU tools
Within the desktop version of SU however, with the help of a plugin https://sketchucation.com/plugin/2106-sb_trilateration, you could design it .

There are other free ways to do a accurate trilateration-survey.
You could use this open source parametric CAD program http://solvespace.com/index.pl to design the floorplan.
From this program you can export the 2D view as a .dxf file and import this .dxf in to the pro version of Sketchup.
Or you could then, for free, convert the dxf into a .skp file with https://pcon-planner.com/en/download/
now you can also upload this file into the free online SU version.

Bep

Don’t be too hard on SketchUp, @Geo.
First we had no way of finding the intersection of an arc and a known edge. Till we got the ‘Pie’ tool. Now we just need that extra step where SketchUp remembers an arc in its true form to intersect with the ‘Pie’ tool. I’m confident (hopeful) that one day we’ll get that extra step too.

2 Likes

The available Trilateration (extension store or Sketchucation) plugins can be used to solve this problem accurately until SketchUp comes up with, for instance, true guide arcs/circles.

Hasaf,
This is a good opportunity for your students to learn the importance of actual field dimensioning.
And also to explore creative ways to nail down off angle walls “as built”.

Taking an equal dimension in both directions “off a corner” (marked on blue tape/other) and then recording the distance between the same “equal” dimensions is one way to get better accuracy to actual field conditions.
Also, should a discrepancy arise, it can guide you to further source of potential “out of square” as built walls/etc.

I recommend the students re-measure at least this specific room as an exercise to find the discrepancy…please see .skp scenes for visual aid.
Field_Verify_Basic B_111.skp (330.4 KB)

Charlie

1 Like

I want to thank all of you for your help with this. I realize that I was not the best tempered of requesters for information, I hope that all can understand that I was in a frustration state (not in the least added to by the could just imagine into being, a set of lessons for the advanced students who have already finished this semester lessons in most of their classes . . . what’s next? A 1:1 model of the Taj Mahal out of soap and sugar cubes. . . but I digress. . . )

Someone posted a short video of how to use the arc tool to do what I needed. I really appreciate that. I can no longer see the video, and I have no idea why, Once I saw how it was done, it was easy to reproduce.

As I said, we only have a few of these oddly shaped rooms, I just happen to be one of them.

I do happen to think it is a good project, It was just a bit of an “I’m going to do what!?” when it was dropped on me. Again, I do appreciate the assistance, your helpfulness and courtesy were certainly more than my tone warranted (yes, I am very aware that I came off as being a bit grumpy).

2 Likes

The video was removed by the poster as it didn’t show the tiny inaccuracy that was discussed after it was posted. It is still a relevant method despite the very tiny inaccuracy caused by the segmentation of the arcs. Certainly well within tolerances for the average builder, about half a millimeter over the 3.6 m length. So I have reproduced a version of his gif and included showing the inaccuracy and it’s removal. I also grouped the geometry first to make it easier to delete the arcs after you have finished with them, unfortunately this tends to not show when I have selected the edges underneath before using the rotate tool.
Pie

1 Like

And Box nails it. Elemental geometry in SketchUp to solve it. Exactly what I was imagining from the start as I read through the comments. :slight_smile:

@DaveR already posted this, but as mentioned it doesn’t truly solve the issue. So I’m afraid I didn’t nail anything, just reproduced what is common practice.

4 Likes