Advanced Positioning and rotation of lines/elements


#1

I am relatively new to sketchup, I have been using it since a few years although only for simple projects (no architectural work), so I guess I more or less know the basics, but sure I am no expert.
That being said, I am currently dealing with some projects where I have to design intricate tube frames, and I do this by designing lines and then using the pipe along path plugin, which is just great for my needs.
The problem I am facing is placing the different parts (lines) in the desired position so they intersect in 3d space. Extrusion with the plugin is done only after all lines are positioned as it is obviously easier dealing with a line than an extrusion.
Now, I have a problem with placement and rotation of the “lines”.
I would like to “join” different lines resting on different planes and not on the x y z axis and rotate lines on the axis running through the start and the end point - i.e the “joints”.

I attach two snapshots:

Snapshot 1 illustrates the problem in dealing with moving one line upon an other - or upon predefined points in space

Snapshot 2 illustrates the problem in rotating one “line” after it is placed in desired position - in case there is a solution to problem 1

Hopefully there is a solution or a viable workaround. I got used to and love sketchup and I’d hate to switch to someother software.

In a “traditional” cad software I’d probably move the elements by defining points in space and snapping the ends onto them and/or on a path. The rotation could be simply accomplished defining two points on the rotation axis and flipping the selection around it.
I am short of ideas how this can be accomplished in sketchup.


#2

Have you tried just drawing the center lines of all the tubes in place? That would eliminate the need to move them into position.

If you do need to move them, you may find it easier to make the lines for each tube into a component so they don’t stick together.


#3

Not sure I got what you mean exactly. Anyway designing the whole assembly in place is not possible since I am forced to start by importing a 2D dxf into sketchup due to workflow constraints. I then explode the import and start moving the lines around in order to give the assembly the 3d dimensions.


#4

OK. I get it. You don’t want to change your work flow. So, as you say, the rotation axis can be easily defined and you can rotate the selected edges. Or, as I suggested, you can make a component (or group) of each set of lines and rotate that into position.


#5

Maybe this pic gives you an idea how I am working.
Selected (blue) entities are those that were “moved” (actually redrawn) to predefined points in space and extruded to tube. Problem is when I move the connected entities the whole geometry will change.


#6

That’s why I suggested:


#7

I will experiment your suggestion.
As to the rotation. Any chance to rotate an object around an axis different than X,Y or Z ?
Say I want the the “3piecealmosthorizontal” tube on the right to “protrude” more from the 2D import. Any chance to rotate it along the axis connecting going through its edges ? Dragging along the other connected tube on the left would be ideal so I dont have to redraw that part separately.

Thank you so much for your suggestions.


#8

You can rotate along any direction. You just need to set up the Rotate tool for that. You might find it useful to place guidelines to identify the axis of rotation as a “line”. You can also use the Move tool to move endpoints if that’s what you need.


#9

As you can see in the second pic I defined a guideline, but can’t manage to set up the rotate tool to snap on that axis. I understand when the tool is black it’s set on a “different” axis, but can’t find a way to constrain it to “my” axis…


#10

Click on the guideline and hold the mouse button while you drag along it. When the protractor stands up the right way, let go of the button. Proceed with the rotation.


#11

Owe you a beer !!
And what am I supposed to do in order to move just one of the two endpoints of my line ?
Making the line into a component dont seem to help although its no longer sticky. That was another great piece of advice.


#12

If you have a set of edges you’ll be using to make a tube with the plugin, open the component for editing and grab the endpoint with the Move tool. Move it where you need it to go.


#13

That is still changing the geometry of my line.
Unless I select the whole line as I edit the component and grab the endpoint.
But then the whole line moves, not just one end point…


#14

How do you mean it changes the geometry of the line? How are you defining a “line”? Is that a single edge or a collection of edges? What is it that you need to move? Just an endpoint? A whole line?

It’s too bad you aren’t interested in just drawing the edges in place. You’d wind up doing a whole lot less screwing around trying to get things in the right place.


#15

Perhaps Gumbo is trying to do something like this,
It’s the first sequence that comes to mind. (That works anyway)

Shep


#16

I refer to a “line” as in they are in pics 1 and 2. A set of lines, a collection of edges as you put it. I’d like to move just one of the two endpoints of that collection, without moving the whole line or altering the geometry of the collection.
Drawing the lines in place is what I have been doing so far in the example I posted above. Trying to find a way to move what I import without defining points in space and redrawing lines, which is time consuming, and subject to several redraws in case “lines” need be moved.
I need to reproduce the 2d import in a certain fashion, can’t buid the assembly to my liking setting arbitrary points.
Basically what I am trying to do is turn a 2d drawing into a 3d model.
Medusa 4 has some advanced tools in that regard, more advanced than Autocad, but its of little help to these specific drawings beside being very much user unfriendly IMHO.

@ Shep, yes, basically moving just one edge of the collection is same as rotating the collection around the other edge - previously moved in place.
Defining a plane/guideline for the collection to rotate upon could be an idea.
Just grabbing one end and snapping it onto a path would be so much faster though ! Too bad this function is not available.


#17

So then using Rotate or Move. If you don’t want to change the lines inside, don’t open the component/group.


#18

Not opening the component group still wont allow one endpoint of the collection to be moved independent of the oher though. However, combining two rotations on standard axis of the component will eventually snap one end of the collection onto the other. And then it can be made to stand up the right way by rotating it on the endpoints axis. Basically takes one move and three rotations to combine the two collections. Not the fastest thing to do, but still a workaround. Probably faster rebuilding on predefined points as you suggested, although this could be an option in case only some parts need be moved a little.


#19

If you know where the endpoints need to be, it shouldn’t be difficult to draw lines between them in the 3D space. Between setting guide points, guidelines, inferencing and even setting the endpoint of an edge with either absolute or relative coordinates, you should be able to just draw the edges without needing to move points around much if at all.


#20

an example source file would be helpful for suggesting workflows…

john