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i'm modeling a fairly simple sink- completed it and the deleted it by mistake (don't ask).

i now can't recreate it and need help.

the inside walls are a tapered ellipse; the bottom is made from four loft sections.

after joining all these solids, i need to fillet the bottom inside edge (which i figured out how previously or got lucky)- the problem is now when i do that, the fillet doesn't effect the bottom surface and i am left with an edge that sticks past the fillet.

any help would be greatly appreciated... should i use the techniques posted for a elliptical cone rather than the loft surface?

if there is a way to upload images here let me know and i will.

thanks.

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i've found a workaround for the above problem...

creating a loft surface out of a quarter ellipse joining down to a quarter circle, i get one 'quadrant'. this seems to fillet perfectly.

the only problem now is that after mirroring them to create the full ellipse shape, the program is taking a looong time to 'join solids' (it may not even complete as it's been churning for a half hour now).

i tried converting to generic solids to see if that helps but no luck.

any suggestion on how to achieve this without grinding to a halt?

thanks.

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I've just been looking at this, and I'm not sure what you meant when you said "the bottm is made of 4 loft sections".

Generally though, the Fillet tool is unreliable and has always been so. After many, oh so many times trying to use it, I've found that it "usually" works, but often not, and with no apparent reason.

I'm now of the opinion that the Solids Engine that NNA licences is just not "up to the task" for the complex solids operations that NNA is trying to get it to do, despite the best efforts of the engineering team.

Back to your problem though, If I loft between a pair of NURBS Elipses and Shell the result I get a basin with a solid bottom and I can fillet the inside edge of it.

It's generally a good idea to list out -step by step the things you are doing, then someone can attempt to replicate it.

Oh, and it's always a good idea to indicate the system and software you're running.

cheers

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nicholas,

thank you for the reply and i'm goint to apologize now for the long response:

1- my initial problem

the sides of the sink basin were made by taper extruding an ellipse.

the bottom was made by trimming a 2d ellipse into four equal parts by bisecting it each way with a line. i then converted these elements into nurbs, moved the end points of the lines (which would be at the center of the full ellipse) down the z-axis. i then used the loft tool to make a sloped plane. i mirrored this three times to recreate the full ellipse shape, and then added all the solids together and then added solids with the side.

the problem was that the fillet effected only the edge only belonging to the side piece and left the bottom group of loft surfaces unfilleted.

2- progress

i realized that lofting the quarter ellipse as i was created the same shape as a drastically taper extruded ellipse. so i recreated the bottom shape this way, added this solid to the sides and it seemed to fillet fine.

3- next problem

technically, this shape does not represent the sink bottom. to be truly accurate i needed to make using the loft technique again. this time i drew and ellipse for the outside shape of the bottom and a circle at it's center for the drain. i then bisected it each way with lines and trimmed everything to a 1/4 quadrant again. i then lofted this surface- the difference is that it creates a warped plane rather than a tapered cone, which is technically correct as the edges of the bottom slope non-uniformly to the edge of the drain circle.

i then took a 1/4 ellipse for the side and taper extruded it and joined this solid with my 1/4 warped plane bottom. after joining these the fillet worked fine.

the problem is that if i try and join 4 of these to create the full bottom, or if i try to subtract any one of these solids from the outside shape of the sink, it locks my computer up. i left it spinning for 10 hours overnight.

is any of that clear?

my system:

ibook g4800 mhz, 640mb ram, os10.4.4, vw11.5

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3x3x3 - after quite a lot of experimenting I managed to do it.

The trick is to use an ellipse for the centre hole in the bottom. Then the bottom will loft in a single piece rather than 4 quadrants. (draw an ellipse and then adjust its size with the OIP so it is the same dimension in both the x and y directions). It took two goes though:

- from small ellipse to big ellipse resulted in 4 quadrants again.

- from big ellipse to small ellipse resulted in the desired one piece.

The method I used was as follows.

- Draw two ellipses for the sides, convert these to nurbs, adjust their z heights and then loft between them.

- Draw two ellipses for the base, convert these to nurbs, adjust their z heights and then loft between them.

- Assemble the two parts together and add solid.

- Rotate the view so you are looking at it from below and apply a fillet to the joint between the two parts.

I couldn't get it to shell though. Perhaps if you try shelling first and then apply fillets to the inside and outside surfaces at the join it will work. Good luck.

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Shelling does produce a uniform thickness so your method would be more accurate.

A lot of the 3D modelling is finicky. Sometimes things work and sometimes they don't. Experiment - sometimes a different sequence of applying fillets will work. Lofting is a bit the same - always hit the preview button before you confirm the result.

Lofting is often more successful when the objects are the same type or shape. I think that is why the ellipse for the centre hole worked when a circle wouldn't.

After my previous post I recalled a bathtub modelled by Luc Janssens. There is an image of it here:

http://www.nemetschek.net/gallery/show_image.php?id=314ℑ=large

You can also download the file of it from the 3D Powerpack area:

http://www.nemetschek.net/3dpowerpack/samples.php

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I've had a few more goes at this with little success. :-(

Generally; Lofting can produce some very complex surfaces and I've used them a lot. Certainly VW is capable of making some quite sophisticated forms.

VW however seems incapable of lofting between a circle and an elipse. You wouldn't have thought that it would be such a big deal. Every time I've tried it the result has been a group of about 9 surfaces rather than 1. What's worse is that the individual surfaces cannot be Composed into a single surface.

It was able to make a Multiple extrude between a circle and an ellipse happily, but that results in an object with a bazillion facets, and not a single surface. Not really what's wanted.

I tried quite a few techniques to make the elliptical basin with a round plug hole, and haven't succeeded yet.

I don't have the broad experience to know how well this task would be handled by other NURBS modeling programs, but I suspect the difficulty, (and the irritatingly pernickety behaviour of VW in the order, direction, and sequence of tasks required to get a job done -if at all) comes back to the "economy brand" Solids Engine they use. Perhaps if they licenced the ACIS engine or similar we could concentrate on designing and not on spending hours of juggling trying to get the software to make simple shapes.

I doubt though, that many users would want to pay the serious impost on the cost of their software that licencing a better 3D engine would inevitably involve.

I'll have a few more goes at the basin and see what I can get.

N.

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Nicholas - Like you I was a bit frustrated by the segments that a circle to ellipse loft gave. Then I thought well the ellipse to ellipse for the sides doesn't do that so why not use ellipse to ellipse for the base, with the plug hole ellipse being an ellipse (oval) with equal dimensions. Worked fine.

Prior to that I unsuccessfully tried modelling it in one piece with 3 ellipses, and then 5 ellipses with the middle 3 very close together to try and get a tight curve at the transition from the bottom to the side. Neither worked real well so I resorted to modelling the two pieces separately and then solid adding them.

3x3x3 - Instead of solid subtracting why not model the inner and outer shells separately. You could then use extract curves to create the connecting surfaces and use add solid to create one object. The fillets you require could then be added to this object. (PS - you have to satisfy our curiosity and tell us how you managed to delete the first one.)

[ 03-17-2006, 07:44 PM: Message edited by: mike m oz ]

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this seems like an interesting discussion indeed... and a more complicated task than i had imagined.

the lofting between the ellipse segment and circle segment seemed to work for me, allowing me to fillet also, but the shape became unusable. i couldn't tell whether i was working with a single surface or multiple as every time i tried to 'add solid' or 'subtract solid' it would hang my machine up indefinitely.

mike, i was trying to model the inner and outer shells seperately, but thought subtracting one from the other was the most efficient way to create the final shape. i'm not entirely sure how to go about extracting the connecting surfaces (do you mean the upper rim?), but i will give it a shot.

i'm interested in any more comments as well and will fill in my own- a warped plane seems like a complicated geometry but i would think that's what these programs are for.

on an off topic, what other modeling software do you have experience with that might work better? i've used form-z a little but actually mostly in 2d. i would think that a 3d modeling package is only as good as 1) it's ability to render or 2) it's ability to export shapes so they can be imported into another rendering program.

that brings up limitations of the rendering program. for example. if this model is so difficult to create in vectorworks, how well would it export to artlantis?

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3x3x3, I am an architct so tend to stick to architectural packages - my work has to be buildable.

VW's modelling free form capability is pretty good from what I have seen. There is a wealth of information in the 3D Power Pack area including movies, tutorials and samples which will help you understand the capabilities better. Take the time to look at the information available. It will help you a lot.

Also have a look at the other relevent NNA movies in these areas:

http://www.nemetschek.net/upgrade/demos.php

http://www.nemetschek.net/upgrade/11demos.php

Archoncad's Jonathon Pickup also has some podcasts on his website that show how to tackle some 3D modelling issues:

http://web.mac.com/jpickup1/iWeb/Site/Podcast/Podcast.html

Your 3D models should export to Artlantis okay, but why not use RenderWorks? You then have the advantage of doing everything in the one program.

[ 03-17-2006, 08:24 PM: Message edited by: mike m oz ]

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mike, i am (or was) an architect as well. i've always liked the idea of vw all in one package- but i also don't want to run into many modeling limitations. i realize i am working on fairly simple geometry so it's probably not an issue.

as for rendering... i may be trying to get as realistic renderings as possible, and i've read that artlantis is more up to the task than rw. is that your experience? is it possible to get photo realistic renderings out of rw?

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I'm not a fan of full on photorealistic renderings because of the inordinate amount of time you have to spend on modelling and rendering to get them looking right. A more loose artistic look, like Piranesi can produce, is better in my view.

The Photoshop 'Denis Technique' featured in the SketchUP forums produces very nice results as well. http://forum.sketchup.com/showthread.php?t=47101&highlight=dennis+technique

Look for the PDF document towards the end (To download it you will need to register first - the first change since the Google take over of @Last )

Cinema 4D and Artlantis are your best options if you want to do photorealistic renderings better than what RenderWorks can do. Both have plug-ins for VectorWorks.

[ 03-18-2006, 12:52 AM: Message edited by: mike m oz ]

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mike- thanks for the effort in helping.

i will try this and see if i can duplicate your success.

when you said you couldn't shell it, is this a technique i should be using? i have been creating the inside solid and then subtracting that solid from an outside one. wouldn't shelling the inside shape only create a uniform thickness?

also, is lofting a problematic method when working in 3d?

thanks.

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so i've had a chance to try out mike's method and i have mixed results (possible my fault).

lofting between two ellipses for the side and two for the bottom works fine, and fillets without problem.

the problem is when i try to model the exterior as an extruded ellipse and then 'subtract' the inner lofted shape from the outer ellipse- the program performs the action, but when i render it as a test i can see that it did not create a hollowed out sink/basin- all that appears is the solid outside extruded ellipse.

i tried playing around with extracting curves and faces to combine solids but didn't have any luck.

what's also strange is that for the final shape, the top rim (which is 1/2" wide) also needs to have two 1/4" fillets- not realizing that the 'subtract solids' hadn't worked i was continuing along to the end of the model- when i filleted the inner top edge, it seemed to fillet fine. when i went to fillet the outer top edge the out ellipse shape suddenly disappeared (i got the same results repeatedly).

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3x3x3 - download Luc Janssens's bathtub from the 3D Powerpack area and look at how it has been done.:

http://www.nemetschek.net/3dpowerpack/samples.php

Make a copy of the file and explore it:

- Ungroup will remove fillete.

- Edit Group will step you back through solid additions and subtractions.

- Further Edit Group's will step you further back in the history.

Once you understand Luc's process you will then know how to do your basin to produce the good result that Luc did..

[ 03-18-2006, 08:25 PM: Message edited by: mike m oz ]

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hi mike,

i had seen that tub awhile back but never really explored it. i will make a point to do so and see what i can learn..

would you know if there is any information on the rendering technique? it's very expressive without being too literal.

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I've looked at that file in the past and again now with VW12, and the usual outcome is that the Fillet edge tool fails to work on the bottom inside edge of the tub.

I have got it to work once, but generally -whether its that file or a new file made with (what I infer is) the same process; the fillet edge tool will fail for me.

No: tell a lie; I just had another go at Luc/ Brammello's and the Fillet Edgeworked OK this time. In fact it's worked every time this time

quote:

Originally posted by 3x3x3:

hi mike,

would you know if there is any information on the rendering technique? it's very expressive without being too literal.

It appears to be 2 coincidental duplicates of the same object: one with a None fill(the lines), and the other with a texture with about 50% transparency (the "solid" bit). That'd be my guess anyway. ;-)

N.

[ 03-21-2006, 02:44 AM: Message edited by: propstuff ]

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nicholas,

do you think it's a matter of vw12 vs. 11.5? i will look at the model again, but i'm having a difficult time getting much information by ungrouping etc. (just my inability to learn that way i think).

thanks also for the rendering tips... i will do some experimenting. is it possible to export a specific view such as those into a illustration program so that the lines are editable objects?

also, to follow up on a previous question (and somewhat unrelated), what is the utility of loft surfaces? it doesn't appear that they are solids and so cannot be joined.

thanks again.

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do you think it's a matter of vw12 vs. 11.5?

It's possible; I would say the tools have improved in reliabitlity over the versions.

Of course, it could just be me.;-)

i will look at the model again, but i'm having a difficult time getting much information by ungrouping etc. (just my inability to learn that way i think).

After you have ungrouped to remove the fillets, the OIP will tell you what sort of object you have.

Double click (to edit)the main solid. In the top right corner of the mode bar a button will tell you what sort of operation has just been undone. etc etc

is it possible to export a specific view such as those into a illustration program so that the lines are editable objects?

Exporting as an EPS should give you editable vector lines (I think)

also, to follow up on a previous question (and somewhat unrelated), what is the utility of loft surfaces? it doesn't appear that they are solids and so cannot be joined.

Lofts produce NURBS surfaces which "can be" joined if conditions are right. If their edges are contiguous the Compose command or the Add Solids command "should" work. In some circumstances the Combine/Connect tool will join them.

In the Bathtub, I would say that the original solid was made by lofting between 3 NURBS Elipses and choosing the Create Solid option. This gives a Solid Addition object. If you double click it, it will be 3NURBS surfaces.

NURBS in VW are powerful, but pernickety to use and understand.

I'm too ignorant to know if this is true for other NURBS modelers.

HTH,

N.

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