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mmyoung

brief lofted solids primer

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In the Solids Modeling section, a user inquired about making shapes in VW that are similar to things Zaha Hadid likes to make, so I posted a rough primer. Not an award-winning model, but it shows some of the possibilities for making shapes by lofting simple NURBS profiles.

People have asked about things like this often enough I thought I'd post it here, too.

To follow the sequence, go to Saved Views and you'll see a numbered list of frames.

All the best ?

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Michael,

Nicely laid out demo! Some great detail about some of the more complex tools and how to use them.

As someone who owns a copy of Jonathan's book, I can say there is some good material in it. Certainly a great start for beginner/intermediate modelling and for a more traditional architectural approach.

Unfortunately we are still missing a resource that really talks about the various 3D objects and their advantages and disadvantages (ie. nurbs vs. solids vs. 3D polys etc.). After a year of some serious 3D use, its become clear to me that the key to a successful 3D workflow in Vectorworks is thinking through the process of building the 3D object first. This often means some trial and error objects as one experiments to get the order and process right. It also means a more methodical, less organic design process. (The process may be much simpler for architecture, but everything I have been modelling is non-modular.) I have begun to understand a desire for a non-linear modelling process (ie. Spaceclaim) that others have talked about in these forums.

Kevin

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I agree with Kevin, a really great demo, much better than I have seen, although I do not have Jonathon's manual so it doesn't seem fair to comment, and yet the process or order of execution does seem to be important to get the best out of the VW software, certainly as the model gets more complex.

For instance, adding a several fillets to something means that I have to write down what I have done before ungrouping so I can re-apply them after editing the underlying object.

When converting surfaces to NURBS to create a 'Fillet Surface' is a pain because it means that the edit history is lost.

Spaceclaim or even Solidworks do seem to offer a more fluid solution, but then again they are more mechanically based and VW does seem to cater more for the architect.

It's just about having the freedom to edit the object as it is.

Why can't I just grab a fillet and enlarge/reduce it by dragging or why isn't it included in the 'Edit History Tree".

Why can't I edit the path from 'extrude along path' in a 3D view with the other objects available to snap to.

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In the Solids Modeling section, a user inquired about making shapes in VW that are similar to things Zaha Hadid likes to make, so I posted a rough primer. Not an award-winning model, but it shows some of the possibilities for making shapes by lofting simple NURBS profiles.

If possible, any chances of exporting to 2009 and posting for those of us that do not have 2010. I assume a version earlier than 2009 may not be as relevant due to lack of Parasolid.

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A quick note.

Using the file saved as 2008, the resulting loft is a generic solid.

However, a loft using the technique creates a solid addition consisting of nurbs surfaces (or a group of nurbs surfaces if "solid" is not selected when generating the loft).

And of course...make sure your profiles are NURBS.

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Hey brudgers,

Yeah, thanks. I meant to mention that but it probably didn't get into the notes. After you make the loft, you have to convert it: Modify > Convert > Convert to NURBS. I think that'll work. Then you should be able to push it around with 3D Reshape. Which is somewhat of a bear, unless you have the work planes working in your favor.

One of the niceties 2010 is that although the functionality is the same, the plane are easier to see when you are installing them.

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Hey brudgers,

Yeah, thanks. I meant to mention that but it probably didn't get into the notes. After you make the loft, you have to convert it: Modify > Convert > Convert to NURBS. I think that'll work. Then you should be able to push it around with 3D Reshape. Which is somewhat of a bear, unless you have the work planes working in your favor.

One of the niceties 2010 is that although the functionality is the same, the plane are easier to see when you are installing them.

Does 2010 create the loft as a NURBS?

2008 does. I thought it was a conversion issue.

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No, it creates it as a generic solid, and you have to convert it. Is this an advantage?

I don't think so based on the limitations of Generic Solids under the old (2008) modeler.

Under parsolid, it may be different.

The attached file shows a loft with the solid option selected.

The contents of the solid addition were cut, pasted and grouped.

then individually colored/textured.

I don't know how it compares to the same process using parsolid.

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Hi brudgers,

In v2010, the Loft tool creates a generic solid, which you can Modify > Convert > Convert to NURBS. But if you leave Create Solid unchecked, it creates a group of NURBS surfaces, like in v2008.

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Ozzie,

If I had Landmark (as Alfresco does), I would make a TIN (a "Triangulated Irregular Network") with my surveying points, from which it is much easier to make a plausible surface from a point cloud than it is with NURBS surfaces.

Without LandMark, as you suggest, you'd like to make the model using NURBS surfaces. Bunch of ways to do that. I'm not precisely sure what you are seeing in your imagination, so here's a guess.

I began by tightening up the existing model to eliminate overlaps and address the low corner of the intended driveway. Executive decision... ha ha. It's easier to edit NURBS curves that surfaces, so do as much editing as you can before surfacing your curves.

You are aiming at making a set of NURBS surfaces which correspond to your surveyed data points. To do this with NURBS, I would lay in my data points using 3D loci: Pop in a locus, then edit it coordinates in the OIP. Draw NURBS curves through the loci and make surfaces.

You could also make interpolated surfaces, which are guaranteed to intersect all the data points, but getting the UV lines oriented well to your data points would be difficult.

Edited by mmyoung

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