Guidelines on a circular object

Suppose I have a circular object, like a tube and I want to have a guideline 1" from the end and have that guideline travel the circumference of the tube. How would I do that? All I can get is a straight guideline on one side of the tube.

I’m new so there is probably a better way but I’m thinking something like this.

I took a copy of the bottom circle and moved it up.

SketchUp does not really have Circular Gudies (yet. Ie, we’ve requested them.)

But since circles in SketchUp are just a collection of connected edges, we can fake them for awhile. There are some plugins around that can convert a circle to a group of guide lines.

So you’d do similar to what @appliancejunk shows, but I’d first move it down clear of the tube, do the convert command, then move the group of guides up to where you need.

I tried out “Construction Line” by daiku

But, you have to manually group the ring of guides after the conversion.

So the workflow is:

  1. Copy the bottom down completely clear of the tube, using the MoveTool and holding the CTRL key (till you have the axis of movement, then enter some easily remembered value like 10.)

  2. Select the circle, and right-click and choose daiku’s command “Convert to Construction Line” from the popup context menu.

  3. Window select the entire ring of individual guide segments, right-click and choose “Make Group” from the popup context menu.

  4. Activate the MoveTool and move the guide ring group upward, then enter the previous “moved down” value +1 into the Measurements box.

1 Like

Like this?

If so could you explain why that’s a better way. I don’t doubt you it is, I’m just trying to wrap my head around what’s going on when it goes from a circle to a polygon.


Not polygon, John.

You need need to go Window > Extension Warehouse.
Then install daiku’s “Construction Line” extension.
It adds a “Convert to Construction Line” right-click menu item.

Ok, I took a look at the extension. So then what would be the advantage of converting it into a construction line. Can’t the line be used as it is for a guide even though it’s not shown as a dashed line like a regular construction line?

Regular edges within the same context interact geometrically. The circle would cut the outer surface into an upper and lower.

Guides are used for inferences and when you do not wish to cause geometric “complications.”

Fredo’s Curvizard is another that has the guide option.

1 Like

You could do it this way. Just place your lines within a ‘Group’, so as to isolate them from the other geometry (which @DanRathbun warns about). . . OR, for that matter there could be strong arguments for making them into ‘Components’ instead.

I often draw up alignment jigs, turn them into components, and then move them around on my model for use as reference points for a variety of things. In some ways this is even a big improvement over standard guidelines… because you can model your jig to reference 3 dimensions which conventional guidelines don’t do.

Having said all this… I’m all in favor of have extended guideline options. And I’d love to see Polar Based guide options come to SketchUp.

So why not make a layer called “Guides” and dump groups of geometry onto it?
Personally I would select the bottom circle, group it,** and move up by 200. (Since the act of grouping means it won’t “stick” to other geometry it touches)

** maybe insert “copy, explode, paste in place” into that work flow if the “guides” I want also involve surfaces - if you group lines that form edges, then it will copy that line into the group rather than destroy the surface it’s bounding. If the guidelines are something I want to refer back to, then I would name the group so that I could find it again in the outliner.

Hi You could pull the circle down and group it and the then hide it . If you turn on hidden geometry it will show up dotted.

For me, because 3 months from now, I will not remember what geometry is masquerading as guides, and it’ll freak me out when I see normal geometry not acting like normal geometry. And I myself only put CLines and CPoints on layers named “Guides”.

But… SketchUp is multi-paradigm. If that works for you, go for it.