Hi Michael,

Thanks for the clarification on the tangent's behavior in Moi, I'll experiment further more.
I imagine I can use the freeform tool more than I do presently, It seems to work pretty well and the fact that the align command works on control points is quite amazing.

I used to work quite a lot with Autocad in a previous life, so I thought tangent operated in a similar fashion while constructing circles.

I remember a small script I've written in Autocad, It was useful to trace sketches.

1. -The first point was picked on circle or arc (with the tangent snap constrain)
2. -Then it paused for user input for a second point. (which was the middle of three points)
3. -For the last point the tangent constrain was turn on again. If the user selected a point not passing through circle or arc, it canceled the constrain and the last point could be positioned anywhere.

The project I am currently working on is a sweeped violin fiddle head, I really enjoy doing those kinds of shapes with nurbs (and especially with Moi viewports).

I had a Dxf 2d reference but somehow I lost precision while translating the dxf to AI path, endpoints were not connected and stuff like that. I ended up retracing it with the freeform tool using the trough points.

Regards,

Marc

Hi Marc,

> I imagine I can use the freeform tool more than I do presently,

You mean for tracing an outline? Yes, that's probably generally your best bet. After a bit of practice you can get more used to how it works, you'll kind of place your points slightly to the outside of the thing you're tracing so that the actual curve that is sort of shrunken down a bit from those points will go along the trace line.

One thing that is good about that is that it makes it easier to create a single long very smooth piece. If you trace with arcs, you'll tend to get stuff that is split into more segments and you'll generally only get tangent smoothness instead of a higher degree of smoothness...


> I used to work quite a lot with Autocad in a previous life, so I thought tangent
> operated in a similar fashion while constructing circles.

It's been quite a while since I have messed around with Autocad, so I don't quite remember how that works. Was this one of the things that got handled specially if you typed in "tan" before picking the first point?

One thing that is a little different with MoI is that MoI only has the equivalent of a "running object snap", it doesn't really have any concept of a single-shot special object snap like that.

But I may be able to improve this in the future to work more like you expect.

This is one of those things that alters the location of the earlier picked points to true them up to tangent locations, is that right?

- Michael

Hi Michael,

Just for the record have managed to record different examples of tangent behavior.

This example is from SolidEdge, it's the tangent circle creation mode.
It's basically a "2pts on edge circle" with a fixed tangent 1rst point, is has a live dragging of the circle.

http://www.youtube.com/watch?v=7Obe3PcQSVw


This one from Autocad, it is a "3pts on edge circle", in this example: tan, point, point.

The reference circle is in white and in the background there is a gray shape to show an example of tracing situation.
This behaves in a different way as the tangent point will change depending on the two points picked afterwards. The results does not show after the 3rd point has been set.

http://www.youtube.com/watch?v=mBDykzSGk88


I hope this is not too confusing.

Regards,

Marc

Hi Marc, the first one is similar to the Draw curve / Arc / Cont (continue) tool in MoI.

Except that the MoI arc continue tool is limited right now to only working off the end of an existing curve. So with a circle like you're using there, you will need to split the circle by a line into 2 pieces, then you can use arc continue to come tangent off of the end of one of those pieces.

I think it should be possible for me to tune this up so that it works in more situations, like coming off of a circle like you show there.

The 3pts one is somewhat more difficult to tune up, that one will have to wait until after V1, but thank you for putting up those videos to help me understand!

- Michael