self intersecting loft?

[dlevy]

How do I handle a self intersecting loft error?

I have two profiles that touch.

Thanks.

[m***@verizon.net]

Post by dlevy
How do I handle a self intersecting loft error?
I have two profiles that touch.

You've asked enough questions that you should know that such a vague
question can only get a vague answer.

It depends on how the profiles touch and your tangency settings. The
profiles can't "cross", but it might work if they touch at a single
edge. Intuitively, the surface that's created can't create an invalid
solid, if you're making a solid. If you really need something that
selfintersects, you'll have to use multiple features, bodies or
surfaces. Also this often happens if you use tangency or push the
tangency weighting too far.

Or you could just use the magic switch that solves self intersection
problems. That's in the next release;o)

[dlevy]

Post by m***@verizon.net

Post by dlevy
How do I handle a self intersecting loft error?
I have two profiles that touch.

You've asked enough questions that you should know that such a vague
question can only get a vague answer.

I'm trying to be specific. I am essentially lofting two profiles around an
axis. The begining profile is not identical to the ending profile.

Post by m***@verizon.net
It depends on how the profiles touch and your tangency settings. The
profiles can't "cross", but it might work if they touch at a single
edge.

It does touch at a single edge but I still can't get it to work.

Post by m***@verizon.net
Intuitively, the surface that's created can't create an invalid
solid, if you're making a solid. If you really need something that
selfintersects, you'll have to use multiple features, bodies or
surfaces.

That would be fine but I can't visualize how I would break it up.

Post by m***@verizon.net
Also this often happens if you use tangency or push the
tangency weighting too far.
Or you could just use the magic switch that solves self intersection
problems. That's in the next release;o)

[matt]

Post by dlevy
I am essentially lofting two profiles around an
axis. The begining profile is not identical to the ending profile.

If the profiles touch at the axis, this creates singularities and
degenerate surfaces. In some situations it just won't work. There are
examples when this works, but its typically geometry specific.

You haven't mentioned anything about tangency end conditions or guide
curves.

Post by dlevy
That would be fine but I can't visualize how I would break it up.

How about making it one face at a time?

Anyway, best of luck.

[dlevy]

Lesson 3 (Lofts), page 163 of "Advanced Part Modeling" does exactly what I'm
trying to do. It creates a loft about a centerline. It uses no guide
curves.

Post by matt

I am essentially lofting two profiles around an axis. The begining
profile is not identical to the ending profile.

If the profiles touch at the axis, this creates singularities and
degenerate surfaces. In some situations it just won't work. There are
examples when this works, but its typically geometry specific.
You haven't mentioned anything about tangency end conditions or guide
curves.

That would be fine but I can't visualize how I would break it up.

How about making it one face at a time?
Anyway, best of luck.

[SW-Mike]

You may have already thought of this but....

Make sure that when you are selecting you profiles for the loft, you
pick them in consistant areas. If you do not the loft can twist, which
can cause intersecting errors. Also, it is recommended that each
profile has an equal number of entities. For example, if you are
lofting a square to a circle, the square has four lines, the circle
just one. You should break the circle in to four segments, that way SW
know where each point is suposed to go. I don't have the Advanced Part
Modeling manual in front of me, but close the to same page you refered
to, it explains this concept.

Good Luck
Mike

Post by dlevy
Lesson 3 (Lofts), page 163 of "Advanced Part Modeling" does exactly what I'm
trying to do. It creates a loft about a centerline. It uses no guide
curves.

Post by matt

I am essentially lofting two profiles around an axis. The begining
profile is not identical to the ending profile.

If the profiles touch at the axis, this creates singularities and
degenerate surfaces. In some situations it just won't work. There are
examples when this works, but its typically geometry specific.
You haven't mentioned anything about tangency end conditions or guide
curves.

That would be fine but I can't visualize how I would break it up.

How about making it one face at a time?
Anyway, best of luck.

[dlevy]

Dewd!!!
Thank you!
I had to have the same number of entities!!!!

I truly appreciate you taking the time to help me!

Post by SW-Mike
You may have already thought of this but....
Make sure that when you are selecting you profiles for the loft, you
pick them in consistant areas. If you do not the loft can twist, which
can cause intersecting errors. Also, it is recommended that each
profile has an equal number of entities. For example, if you are
lofting a square to a circle, the square has four lines, the circle
just one. You should break the circle in to four segments, that way SW
know where each point is suposed to go. I don't have the Advanced Part
Modeling manual in front of me, but close the to same page you refered
to, it explains this concept.
Good Luck
Mike

Post by dlevy
Lesson 3 (Lofts), page 163 of "Advanced Part Modeling" does exactly what I'm
trying to do. It creates a loft about a centerline. It uses no guide
curves.

Post by matt

I am essentially lofting two profiles around an axis. The begining
profile is not identical to the ending profile.

If the profiles touch at the axis, this creates singularities and
degenerate surfaces. In some situations it just won't work. There are
examples when this works, but its typically geometry specific.
You haven't mentioned anything about tangency end conditions or guide
curves.

That would be fine but I can't visualize how I would break it up.

How about making it one face at a time?
Anyway, best of luck.

[Jerry Steiger]

Post by dlevy
I had to have the same number of entities!!!!

You don't HAVE to have the same number of entities, it just minimizes the
chances that SW will get confused.

Jerry Steiger
Tripod Data Systems
"take the garbage out, dear"

[matt]

Post by Jerry Steiger
You don't HAVE to have the same number of entities, it just minimizes the
chances that SW will get confused.

You can often do the same thing with connectors as with splitting up
sketches.

[dlevy]

Thanks guys.

Matt, you seem to have a problem with my questions. I apologize if they are
too vauge or simple. I do find verbalizing my questions difficult. Hell, I
think the software is difficult. Anyway, thanks for bearing with me and I
hope I can help in the future.

Post by matt

Post by Jerry Steiger
You don't HAVE to have the same number of entities, it just minimizes the
chances that SW will get confused.

You can often do the same thing with connectors as with splitting up
sketches.