Scaling to a guideline



Is there any way to scale a particular curve and have it snap when it intersects with a guide line?

I’ve attached to shots of what this operation would look like.



(Brian James) #2

Hi Ramon,

You can use ScaleByPlane with a Quad (or any other appropriate) Osnap if the scale is non uniform but I believe you want the curve to maintain it’s aspect ratio. In that case, you can do this by relocating the Gumball with the following steps:

With the Gumball displayed for the curve to scale, run the command RelocateGumball and place the origin at the end using Osnaps as shown and the X axis direction using the ultimate desired point of contact… in this case a quad Osnap.

Then hold ctrl down momentarily and click once on the blue arc. Type 180 and press enter.

Next, hold down ctrl while you click and drag the X axis scale handle on the gumball. Drag the X axis handle to the quad Osnap like this.

Lastly, turn on ‘Snappy Dragging’ in the Gumball settings accesible by clicking the little white circle. You can then scale the curve using the X axis scale handle and a Near Osnap on your target line. Hold down Shift while doing so to keep the curve’s width and height uniform.

(Pascal Golay) #3

Scale can do that if combined with snaps and tab direction lock-

When you see that direction lock kick in I’ve used Ortho to force the direction vertical and then hit Tab to lock that direction.



Hi BrianJ,

Great. Thanks. I’ll give it a go soon.


Hi Pascal.

I’ll also try this method.



hey pascal,

does the quad snap give you the uppermost (outermost? i don’t know what word to use here :slight_smile: ) point of the curve?
i’ve done something like your method a few times in the past but i ran the BoundingBox command first then used it for my scale points… i’m thinking that was a wasted step now if quad is doing what i think it’s doing?


[edit] well, yes, that’s what the quad snap is doing… all this time i thought it was doing something else (something less valuable)

(Pascal Golay) #8

Yep- Quad looks for the local point on the curve where the curve changes direction relative to the CPlane axes, I guess you could say, so a wiggly curve might have multiple Quad points you could hit.



Hi all,

Thanks to all, I was able to achieve the desired outcome with both of those techniques only to be caught out by the next phase.
In this particular case I’m trying to scale the curved line to intersect with the uppermost end of the vertical line on the right. I would like the scaling function to “pick” the relevant point of intersection for me. Typically, I do this by eye / trial and error to achieve a result that is within my given tolerances, but would really like to know how be more precise.

Again, I’ve attached a couple of screen shots.




Sometimes I find it just easier to create some “helper” geometry… see below.




That’s great thanks.