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Best Practices: Exploading PIO's

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Hello all,

Yes, I'm still here, poking away at VW,

I was wondering what people found as the best method of un-grouping /breaking apart PIO's.

I ungrouped a cabinet and am left w/ a bunch of Multiple Extrudes which don't seem as versatile a modeling block as a simple extrude.

I specifically am having trouble chamfering the Multiple Extrude.

Any help or advice is always welcome!

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Multiple Extrudes which don't seem as versatile a modeling block as a simple extrude.

Quite contrary. A simple extrusion is a special case of the broader concept of multiple extrusion; thus, much less versatile. In short: there isn't anything a simple extrusion can do that a multipe extrusion cannot. The latter is a superset of the former.

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Many and various, Jeffrey!

Let's eg. consider my "prefab pretensioned (hollow-core or double-T) slab element" PIO. Without "exploding" it, I can't use it to make 3D-booleans of arbitrary (plan) shapes.

The 3D component is either a rotated extrusion or a 3D-subtraction (with the hollow core element, the "main slab" and "the hollows"). While 95% of elements will be rectangular in plan in most projects, the rest are not. No, being able to "clip" the 2D-representation does not work. Besides, as these elements have fixed widths, "line object" is the only sensible method.

So, in order to model certain parts of the building fabric, I need to be able to "explode" PIOs.

Edited by Petri
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Petri is absolutely right about the need to ungroup ("explode" is an AutoCAD word!) PIOs to customize instances in certain situations.

It would be good if NNA engineers recognized the usefulness of this process, and made components of PIOs easily editable. For myself, I find that extrudes and boolean combinations of extrudes are the easiest objects to edit in most situations, but for some reason some PIOs ungroup into generic solids that are difficult to edit.

A good example is the creation of specially-shaped windows. VW could not possibly anticipate all the needs of designers with respect to the shape and configuration of window and door parts. My practice would be to use the PIO to get something close, then convert to a symbol, then ungroup the PIO in the symbol and edit the part. Would be, that is, if the parts of the window were logically constructed of easily modifiable extrudes.

Another example is the current incarnation of the cabinet PIO. It is limited to two doors per cabinet, which makes life difficult when extra lines appear in interior elevations, as a result of having to cobble together a line of cabinets from the PIO. Being able to ungroup the cabinet and then tweak its objects would be the best way to deal with the tool's current limitations.

PS, revit, "multiple extrude" is a specific object that creates a tapered extrude. I think you meant to say something else.

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Petri is absolutely right

As usual...

For the average user out there, it is incomprehensible that he or she needs to "ungroup" or "explode" the same PIO twice: once for 3D, then for 2D.

but for some reason some PIOs ungroup into generic solids that are difficult to edit

Ohh - if they were even solids! We get extrusions, goatherd-lonely 3D-polygons and what have you!

VW could not possibly anticipate all the needs of designers with respect to the shape and configuration of window and door parts.

Precisely. After all, some of us do not do McMansions.

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Thanks for the advice and troubleshooting:

When I ungroup the cabinet, there is a seemingly random breakdown of objects. Some are regular 'simple' extrudes and others are multiple extrudes - both objects being a rectangular box. The problem I have w/ the m.extrude occurs when I go to render it. I need to convert it to something else to get the texture to apply correctly. Unless I'm doing something wrong w/ the textures ie. multiple extrude being more of a circular object and I am mapping with planar/perimeter?

The other problem I am having w/ M.extrude is how to chamfer the edges?

So...is the 'random?' breakdown of PIO pieces caused by the method used to construct it in the first place, and if I begin to script my own PIO's can I set them up to Ungroup how I best see fit?

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revit, again, what you are calling "multiple extrudes" are probably solid additions or solid subtractions.

When you ungroup a PIO, it becomes a group of solids (or 2d objects, if you are ungrouping it in Top/Plan view). These are "ordinary" objects that can be edited like any other object of their type. The nature of the objects has been determined by the engineer that designed the PIO.

Petri, I don't share your feelings about extrudes. To me they are the most fundamental 3d object, easily edited, and rely on the hybrid 2d/3d interface that I think is one of VW's greatest strengths. So I would prefer all PIO objects to be designed as extrudes wherever possible, and I don't see the point of having a set of window muntins or a joist, for example, be anything else. A window sill with "horns" - yes, a solid subtraction would be the way to go. Never a mesh object or a generic 3d solid!

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Petri, I don't share your feelings about extrudes. To me they are the most fundamental 3d object, easily edited,

Not so easily if they have been rotated or moved from the Garden of Eden where they were created.

and rely on the hybrid 2d/3d interface

They are not hybrid - which I also think

is one of VW's greatest strengths.
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  • Vectorworks, Inc Employee

Will, I presume you're talking about door panel inserts on the Cabinet object. When you ungroup the cabinet, you can use the "Enter group" command (control-[) to traverse the hierarchy of objects in the cabinet (as it was drawn by the PIO). You should by selecting the door panel and doing "Enter group" two or three times, be able to select the panel itself, which is a multiple extrude. (I assume you've gotten this far by one method or another.) Once you've got the multiple extrude selected, you can use the Chamfer Edge or Fillet Edge tools in the 3D palette to modify them. Then you can select the panel (which has been converted to a Chamfer or Fillet object depending on which tool you used) and go to the Render panel of the OI palette to play with the texturing. These Chamfer or Fillet objects can participate in solids operations, also. Here's an image. Note the rotation of the textures (this requires a plane and not a perimeter texture mapping) and the embossing of a "text along path" object.

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Ahh, finally, an informed answer! lol

And you were able to provide it w/out insulting me, my country, my ethnicity, or my lack of VW knowledge.

Thank you Robert, that helped a lot.

Let me clarify that what I think is happening is happening:

I seem to be unable to map textures properly to the M.Extrude object. However, when I use the chamfer/fillet tool it converts the M. Extrude to a (chamfer object?) which I can then map using the perimeter setting.

It is disappointing however, that one cannot apply textures to a PIO w/out having to dumb it down. Unless I've misunderstood something here?

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  • Vectorworks, Inc Employee

Will, I haven't done a lot of testing on a multiple extrude object WRT its texture mapping. I'll look at it. You can indeed map using perimeter mapping, however this will limit your options as to mapping itself (you won't, for example, be able to rotate your texture as I do in the example image.)

I agree that the ability to dig down and get to a 'part' of a PIO and deal with its individual appearance attributes (including texture mapping) can be frustrating. (Gotta leave _something_ to do in future versions :)

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Robert, I looked at the ungrouped cabinet, and sure enough, as you say and as revit kept insisting, there are multiple extrudes based on two identical rectangular polygons. I'm left to wonder why in the world a rectangular prism would be constructed from a multiple extrude. Revit, you'll have to pardon me for assuming that an object such as a piece of a cabinet face frame, most logically constructed from an extrude, would actually be an extrude.

Multiple extrudes are commonly used to create objects such as this:


BTW, for my purposes and I think this would be true for others, a cabinet face frame would be best constructed by extruding a polygon that models the entire frame, e.g.:


The joints between pieces are commonly not shown on interior elevations, and if they are, are best depicted by very light, secondary lines. Having the heavy joint lines show up in elevations based on a section viewports makes the drawings look clumsy and unprofessional, so I always have to trace to get usable cabinet elevations (for this among other reasons).

Although . . . if we could suppress the display of selected 3d object edges, and the joints did not then show in elevation in hidden line view, we could then be more sophisticated in how textures are applied. In particular, we could have the PIOs align textures in such a way that wood grain could be properly oriented. That would be the ultimate kind of 3d object. The same logic applies to door frames, jambs, etc.

Edited by P Retondo
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Hey no problem Pete, I assumed the same thing. I'm new to the modeling conventions of VW and wasn't sure if it was simply my inexperience.

Still on the cabinet:

Is there any way to insert user-defined panels. I need to break it apart into 3 equal pieces and put a V groove between them.

Or to adjust the spacing of the drawers. Let's say I want a base cabinet of 4 drawers, but I want the top drawer a little bit thinner than the rest.

Thanks again for the help

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I'm left to wonder why in the world a rectangular prism would be constructed from a multiple extrude.

Pete -

Perhaps to enable future development? One day a vocal user may wish to have a thingumabob that can't be modeled by a "simple" extrusion so if the Engine already does "multiple" extrusions, the wish can much more easily be granted.

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Also have a look at:

Software Customization Services: http://softwarecustomizationservices.com/default.php?page=products

Vectorbits: http://www.vectorbits.com/

Vector Plug-ins: http://www.vectorplugins.com/

Vector Depot: http://www.vectordepot.com/

There is more information on useful add ons and sites in the Community section of the NNA website: http://www.nemetschek.net/community/addons/index.php

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