Hi Guys,

I use Moi3D on a day to day basis to do CNC work. It is by far the best CAD software I ever used. It is easy and simple to make 2d and 3d drawings. I advertise MOI3D to every engineer I meet.

One thing that annoys me quite a bit when making reference designs is when snapping a circle on its center point.

For example If you draw an X and want to place a circle on its intersection you need to draw a line inside the circle and then snap that line to the center of the X.

Is there an easy way to snap a circle from its center? I know it is easy to do the other way around (snapping any object on the center point of the circle) but I constantly find myself placing hundreds of circles and having to draw a bisect line on the circles before being able to place them.

Any suggestions?

Thanks!

Use Transform > Move and use the centre of the circle as the base point.
You could place a point at the centre of the circle and provided you select both items, you can drag & snap from the point whilst in the edit frame.

Martin.


EDIT: Isn't it actually easier to just draw a fresh circle on the intersection point?

Does each line of the X on the same plane ?

Hi hallsadvancedformula, if I'm understanding right you're adding a bisector line so that you can drag both the line and the circle to a new location, dragging from the midpoint of the line (same as the center point of the circle) as the base point?

If that's the case then the main simpler way to do it is like Martin writes above - use the Transform > Move command instead of direct object dragging. The Transform > Move command will allow you to do 2 individual point picks for the base point and the target point, and you can snap the base point onto the center point of the circle. That should then do what you need without needing to draw any additional separate line segment.

Dragging works as a kind of quick shortcut for moving objects around, but since dragging is initiated by dragging from a spot that's on the actual curve itself that won't work for dragging a circle by its center point. But the Transform > Move command allows you to pick any point that you need as the base point, it doesn't have to be one directly on the curve like dragging uses.

In the future I think I'd like to experiment with making a draggable center point that would then enable you to do what you were originally thinking about. I'm a little worried about filling up the working area with special handles though, it can kind of make a sort of screen clutter which I've tried pretty hard to avoid in general. That's one reason why I haven't really jumped into doing that quite yet.

But in the meantime before that is available the Transform > Move command should allow you to do what you need more easily without needing to create any bisector lines.

Hope this helps!

- Michael

And you have the Helpers lines for some tricky help points!

I was just wondering, would it be possible to fuse Move/Copy and Bounding box center into one script?

Hi Marco,

> I was just wondering, would it be possible to fuse Move/Copy and
> Bounding box center into one script?

Yup, that's actually been done already in v3 - for both Move and Copy when you are in the stage for picking the base point there is a "Bounding box center" option that shows up in the command options area. If you click that button the center of the object's bounding box will be taken as the base point for the move:



- Michael

Hi Michael!

Exactly but this specific Bounding box center behaviour isn't really scriptable, is it? Calling the command Boundingboxcenter solely by itself just puts out a point in the center of the box.

~Marco

Hi Marco, you can get the center of an object's bounding box using script - that's actually how the Move and Copy commands do it currently, by this line in Move.js:
    basept = objects.getHighAccuracyBoundingBox().center;

Maybe I'm just not understanding what you're asking about though - I thought you were looking for a way to use the Transform > Move command and have the base point of the move be the bounding box center... That's what the option I showed above will do.

- Michael

i was under the impression, the OP was looking for a way to place circles rather instant by using their center point.



and Move + Bounding box center does exactly that, instantly placing the center of the circle on the cursor...but you can't call this as a shortcut via script or macro, can you?

Hi Marco,

> i was under the impression, the OP was looking for a way to place circles
> rather instant by using their center point.

I interpreted it as more like "an easier process than drawing in an additional line to use for dragging"...


> and Move + Bounding box center does exactly that, instantly placing the center of the circle on the
> cursor...but you can't call this as a shortcut via script or macro, can you?

You can't call the move command itself with that specific option automatically triggered, but it would not be difficult to make a custom version of the Move command that just immediately used the bounding box center instead of asking for the base point at all... It's definitely possible to set up a script for that, let me know if you need to do this a large number of times and I will make that custom command for you.

But for more typical use just the regular Transform > Move command should get the job done a lot easier than their current process.

- Michael

Indeed Marco I was looking for an easy way to drag the center of the circle. While making technical drawings sometimes you need to place hundreds of circles and invoking a command each time is tedious. Since MOI3D snap system is excellent I was wondering there was an easier way to just drag the center of the circle to an intersection.

It is easy to do the other way around. But as Michael guessed. I'm drawing bisect lines so I can snap its center... It is a tedious extra step.

As suggested, I could draw a new circle from a center point... but then I would have to input the dimensions each time. That's also not easy as drag and drop... 50-100 circles to its correct location.

Here is a perfect example:

PLACING drill holes on a faceplate. You first draw the grid with the correct spacing. Then you have to place several circles from its center on the correct intersection. This is an extremely common task... and it would be so much easier if we could drag a circle from its center.

If your circles are all the same size, you can use the copy command, pick the center point, and then copy the circle as many times as you want without having to re-pick or re-enter anything. Just don't press ESC and you can keep selecting target points.

Hi hallsadvancedformula,

> PLACING drill holes on a faceplate. You first draw the grid with the correct spacing. Then
> you have to place several circles from its center on the correct intersection. This is an
> extremely common task... and it would be so much easier if we could drag a circle from its center.

Like Dan writes above, this is a job that the Transform > Copy command is well suited for. It's directly next to the Transform > Move command that should help you with your other circle relocation tasks as described above.

With the Transform > Copy command, you'll pick one base point at the center of the circle you want to duplicate, then you'll stay in the command and click as many target points as you want. Each target point you click will drop a circle into your desired location. It's actually faster than drag/drop would be for placing several objects because you don't have to keep going back to the base object for each copy, you only need to do one click at your target spot to drop a circle there.

It kind of sounds like you're not really taking any advantage of the additional transform tools under the Transform palette on the right-side side pane. Direct object dragging is good for many kinds of simple repositionings, but if you need something more flexible the additional Transform tools should help you a lot.

Transform > Move and Transform > Copy are the most essential ones out of those tools:



- Michael

Also there's an overview of the transform tools here:
http://moi3d.com/2.0/docs/moi_command_reference8.htm#Transform

- Michael

WOW! That works beautifully.

Thanks everyone!