The "ArcCenter" command always constrains the arc to the XY-plane, making it hard to put arcs where needed. For example the center of a box, and the top edge as the start and end would produce an arc that's about 45 degrees with the floor.

Is it possible to make it work in 3D, and have the "keep flat" as an option? And is threre a current workaround?

I can do almost the same thing with Circle3pt and some trimming, but it's not the same.

What about if I hack/edit this line in ArcCenter.js to a false value?
pointpicker.restrictToPlane( arcfactory.getInput(0).getValue(), true );

Hi Anthony,

> What about if I hack/edit this line in ArcCenter.js to a false value?
> pointpicker.restrictToPlane( arcfactory.getInput(0).getValue(), true );

I don't think that will help you for this case, because the ArcCenter factory only knows how to construct arcs in the construction plane that it is given.

Some 2D oriented commands would kind of need additional picks to make them work fully in 3D. Like for instance right now if you want to draw a 45 degree arc, you can use arc center, click the center point and then type in 45, and it's done. If it was more 3d orientation enabled, it would require an extra pick to define the orientation. Extra picks like this can kind of get in the way for 2d constructions.

In version 2.0 I want to make it possible to re-orient the construction plane so that you could use 2D drawing tools in whatever plane you want instead of only the world planes. That is the general plan that will 3D-ify all 2D commands.

Right now maybe ArcContinue (cont) would be the easiest for this job, it will probably more controllable for getting a specific extent like 180 degrees, it will also avoid bulging like you will get with circle/arc 3pt.

Here's an example with ArcContinue snapping on to a box - put the first pick along the edge you want to pivot around, close to the end (but not exactly on the end so there is no ambiguity about which edge you are targeting):



At this point the arc will start at the end of that edge, it will maintain tangency to that edge and you are free to pick the other end in 3d and it will swivel it around whichever direction you pick. So for the second point pick the other diagonal corner:



You can also enter a specific angle like 90 degrees, if you want the arc to stop somewhere before it reaches that second point.

- Michael

The construction plane sounds good -- as long as we can define it by specifying any three points. I tried ArcContinue, but it's not really a good solution for what I'm trying to do. But for now I can get around by using a 3-pt circle along with some construction lines.

Yeah, once construction planes are in there will be a variety of methods to define it, by 3 points, normal to a line, along an existing planar object, etc...

- Michael