Did you know? You can create nurb curves in Revit.

[robmorfin]

Yes, as you read, it's true.

Every time you create a walkthrough path in Revit it is being created by a Nurb curve, it is a matematically perfect curve modificable in the three space dimensions that we all know and live in (X,Y & Z), as our built projects also do, again, x, y & z.

The thing is that only the walkthrough takes advantage of Nurbs, the capability has been there for a while, at least since I started on version 5.0, but it is locked for any other purposes.

I hope the developers decide sometime soon to give us this tool which would give us total freedom for modeling anything that we can think of, Nurbs are way much more parametric and user friendly that splines and they can be deformed or modified in the 3 Dimensions at the same time, the blend tool does not have enough capabilities to fulfill our needs as long as it has a flat & parallel top and a flat bottom.

[robmorfin]

Importing nurbs as meshes is not a modeling option, you loose all the nurb parametrical information and the smoothness of it.

[DanielleAnderson]

Yes, as you read, it's true.

Every time you create a walkthrough path in Revit it is being created by a Nurb curve, it is a matematically perfect curve modificable in the three space dimensions that we all know and live in (X,Y & Z), as our built projects also do, again, x, y & z.

The thing is that only the walkthrough takes advantage of Nurbs, the capability has been there for a while, at least since I started on version 5.0, but it is locked for any other purposes.

I hope the developers decide sometime soon to give us this tool which would give us total freedom for modeling anything that we can think of, Nurbs are way much more parametric and user friendly that splines and they can be deformed or modified in the 3 Dimensions at the same time, the blend tool does not have enough capabilities to fulfill our needs as long as it has a flat & parallel top and a flat bottom.


Awe--the title of your post was such a teaser! Probably intended...

[AP23]

Maybe we just must give it up and accept that Revit was not made for nurbs and complex shapes for obvious reasons. The image gallery is evident of that. If you want organic modeling, you better stick to Rhino, Maya, AutoCAD and 3ds max combo. Trow in a Pro/engineer and Catia for some parametric capabilities. Most Blob buildings and complex shapes were designed and documented in these software, so you know they work well. Autodesk owns 2 softwares (3ds max/vis and AutoCAD) that provides the tools the create organic shapes. I don't think they have any intentions to give Revit the same capabilities as 3ds max and AutoCAD combined.

This is the way autodesk thinks. Revit and ADT are the local all round physicians. They do regular day by day treatments. If you have a headache or athletes foot you can call on the physicians. 3ds max and Viz are the specialists (cardiologist, neurologist ). They do complex work and work in big teams. Interopertability between specialist is crucial.

[hand471037]

Maybe we just must give it up and accept that Revit was not made for nurbs and complex shapes for obvious reasons. The image gallery is evident of that. If you want organic modeling, you better stick to Rhino, Maya, AutoCAD and 3ds max combo. Trow in a Pro/engineer and Catia for some parametric capabilities. Most Blob buildings and complex shapes were designed and documented in these software, so you know they work well. Autodesk owns 2 softwares (3ds max/vis and AutoCAD) that provides the tools the create organic shapes. I don't think they have any intentions to give Revit the same capabilities as 3ds max and AutoCAD combined.

Oh, ****, then I better stop designing curvy buildings in Revit, and switch to the exteremly inefficient and painful AutoCAD + 3DS combo that does nothing to help me actually, you know, make a building.


This is the way autodesk thinks. Revit and ADT are the local all round physicians. They do regular day by day treatments. If you have a headache or athletes foot you can call on the physicians. 3ds max and Viz are the specialists (cardiologist, neurologist ). They do complex work and work in big teams. Interopertability between specialist is crucial.

huh? I mean, to each his own, and I'm not saying that Revit has to be used for everything. But to ignore it's advatanges at actually making the building just because YOU happen to not understand how to make organic and curvy bits in it, or understand that those shapes you want that Revit can't make can be made elseware and imported very easily, well, it's a little silly. This constant complaining about what 'Revit can't do' from folks who don't sound like they have done much with it is getting really old.

[ejburrell67787]

Be nice if someone posted something specific that they would like to see modelled - with enough descriptive information to work from - and let some more epxerienced Revit users give it a go and explain how it is acheived... I'd certainly be up for a challenge if something specific was posted...

...Of course there might be a problem in representing something complex in the first place... usually the difficulty is is coming up with and describing the form that is desired, not modeling it!

I'm sure there would be other takers who like to explore modelling complex forms in Revit, should a specific challenge be posted...

I shall watch the 'Out There' Forum with interest! ;)

[Scott D Davis]

Corbu's Notre Dame du Haut (Ronchamp) was modeled in Revit 2.0, when Revit had very little "complex" modeling capabilities.

Wish I still had that model...actaully, I'll have to check. I think it was on the Installation CD. This is quite an "organic" building. I'd like to see someone take a stab at remodeling it in 8.1, as I'm sure its much easier now!

In any case, heres a photo, credit goes to "Greatbuildings.com" for the image.

[AP23]

This was done in 3ds max.

[dhurtubise]

Scott, i'd be interested in getting my hands on that model to. Let me know.

[AP23]

I've started a tread previously about the import problems. When I import a complex geometry into Revit, my computer freezes. I have challenge some of you to import the file, but no one could have worked with it. So, I'm very curious on what type of organic forms people here are talking about that do import successfully into Revit.

I challenge anyone to make roof and facade out of the model. The model is completely split up into separated meshes representing parts of the facade, roofs, windows etc. so theoretically you dont have to do anything. Just do a roof by face or a curtain wall by face.

Here is the link to the file and pictures
http://briefcase.yahoo.com/alexanderbell77
Users ID: alexanderbell77
Password : blobproject

You need to log in otherwise you can't access the file.

[hand471037]

This was done in 3ds max.

This one was done in Revit.

Oh, and this one knows what Walls are, where the Windows are, and can be exported to Max with that information to boot.

I'll post the whole file if I get permission too.

(This was done with Revit 2 IIRC)

[hand471037]

I have challenge some of you to import the file, but no one could have worked with it.

Well, see, some of us have something called a Job, and I've even got something called a Business, and well, they take up a lot of time. Heck, some people here even have something called 'kids' that apparently take all your time and money too.

Dude. Relax. I'll try to look at your model when I get a chance. But your being kind of annoying, so it's not like I'm tripping over myself to help you out.

[AP23]

Well, see, some of us have something called a Job, and I've even got something called a Business, and well, they take up a lot of time. Heck, some people here even have something called 'kids' that apparently take all your time and money too.

Dude. Relax. I'll try to look at your model when I get a chance. But your being kind of annoying, so it's not like I'm tripping over myself to help you out.

What I meant was, that those people who tried to import the model in Revit, experienced the same problems as i did. That's it. I was not forcing anyone to import the model nor was I complaining that no one wanted to help.

Next time, please read the sentence properly before jumping into conclusions.

[hand471037]

Next time, please read the sentence properly before jumping into conclusions.

Oh wow now I really wanna help you out. Geeze. You're gonna go real far with that attitude there.

[christopher.zoog51272]

I found a copy of it on an Old 3.0 install CD.. Just opened it in 8.1 seemed to work fine, though I am sure if you were to model this again, it would be done differently.

-Z

[christopher.zoog51272]

I found a copy of it on an Old 3.0 install CD.. Just opened it in 8.1 seemed to work fine, though I am sure if you were to model this again, it would be done differently.

-Z
oops should have read the whole thread.

[dhurtubise]

Chris could you share the model ?

[hand471037]

Chris could you share the model ?

There's an issue there. I think the model was done by Paul if I'm not mistaken, but that Autodesk didn't have the 'rights' to Ronchamp (WTF?!?) so that they had to stop handing out the model to folks post buy-out. Or something like that. I'd post the model, but it's not mine, I didn't make it, and so I'm hoping that the person(s) that did will chime in...

[hand471037]

I found a copy of it on an Old 3.0 install CD.. Just opened it in 8.1 seemed to work fine, though I am sure if you were to model this again, it would be done differently.

-Z

Yeah, the walls and roof are all in-place families. The roof is mostly made via voids cutting a solid mass to carve out the complex shape. The walls have voids subtracting out the window cuts, with a small thin Basic Wall as infill for the Window to live in properly.

Now much of this could be done with Massing instead.

[dhurtubise]

let me know if you need access to an ftp
dhurtubise@lemaymichaud.com

[trombe]

Maybe we just must give it up and accept that Revit was not made for nurbs and complex shapes for obvious reasons.


see attached WIP Observatory (project only, very early work). This was a design project during university study but won't bore you with the concepts - I always wanted to have a bit of a play with the project and have it set aside now for some interest value / bit of fun..
2c
trombe

[tatlin]

Yeah, the walls and roof are all in-place families. The roof is mostly made via voids cutting a solid mass to carve out the complex shape. The walls have voids subtracting out the window cuts, with a small thin Basic Wall as infill for the Window to live in properly.

Now much of this could be done with Massing instead.Oh boy, A walk down memory lane here. I think I built this model when we were still developing Revit 3.0 and I think it shipped on the Revit 3.0 CD. I do not believe the dataset or images are used in marketing materials or distributed by adsk anymore for various reasons.

Let me take a second to remember how this was built: First, I traced over imported images of the plan and section using walls and roofs. 'Thick' roofs and walls were made first to conform to the basic shape in plan and section. All the roofs and walls are 'real' and are not inplace families. The host objects were then carved up with a series of voids to make the sloping walls and curvy roof forms. The benefit of this approach is you can retain more 'wallness', like the ability to attach a wall to a roof and host windows, etc. The curvy forms were a great test of the early boolean operations revit 2 and 3 had.

The windows are hosted by the real walls with no thin walls. The windows have a void blend to create the tapered opening and are all parameterized so the single window family definition creates all the different sizes and shapes. I also tested Radiosity using this model. The dark interior, stained glass and stucco textures made for a good test case. We also tested 3d printing using this dataset. We still have Zcorp physical models in our office.

Anyway, this rvt model illustrated some interesting ways to approach modeling in Revit, but looking back on it, it's really not that great of a model! :Oops: Really it's nowhere near as well articulated, refined or advanced as what I've seen in some customer models more recently.

Come to think of it, we used very similar techniques in the modeling classes at AU the last couple of years. Massing makes some of this stuff easier but it still comes back to basic geometry and modeling. I'll see if I can post some of the images from AU classes this year.

The greatest part of this model was a little Modular man that can be seen in some of the images8)

[tatlin]

Importing nurbs as meshes is not a modeling option, you loose all the nurb parametrical information and the smoothness of it.Since Revit Building 8.1, you can import nurbs surfaces as real analytic surfaces and not polymesh representations. You can pick these surfaces using the 'pick face ' tools to create walls, roofs and curtain systems. Here is an example surface that was created in Rhino. Is was made by stitching together four 3d splines and making one wavy NURBS (Non-Uniform Rational B-Spline) surface.

Take a look at the attachement "surf and mesh.png (http://forums.augi.com/attachment.php?attachmentid=17213&stc=1) ". Notice the difference between the right and left images? The image on the left is the smooth ‘analytical’ NURBS surface. The image on the right is a polyface mesh representation. Notice it is a lot courser and not as ‘surface-like’? The mesh has much less information than the surface. You should always try to use smooth analytical surfaces and solids whenever possible. They will give the best results when used in Revit.

You can import this information into Revit if it is contained in an SAT file or a DWG with solids and surfaces. If you import the file into a Mass, you can use the pick face tools to create parametric building objects. in this case we can create a roof assembly that could be constructed out of standard glazing systems, shown in the attached file "nurbs roof curtain system.jpg (http://forums.augi.com/attachment.php?attachmentid=17212&stc=1)"

[mmodernc]

So can you import soap suds and turn them into a building (Beijing Olympics Swimming Centre).
hope there is no copyright infringement here
And of course there is still the good ol corinthian column and umpteen derivatives-still classified as architecture-would it have been a problem modelling buildings in the 18th and 19th centuries if you only had Revit? Solid NURBS right? Thank the 20th Century for Cubism, Modernism and industrialisation. And what about "Hobbit" houses-afterall they are GREEN with thatched grass roofs and all sorts of organic wall and windows shapes. So are the square buildings really the silly buildings?
But really folks-
Is there a definitive comparison of NURBS, polymeshes, acis solids etc and what Revit uses natively, what it imports and manipultes to create a building model and documentation?

[dbaldacchino]

Matt, first of all, your AU presentation was great! I enjoyed it a lot. It was really interesting to see the modelling approaches you took for Gaudi's "La Sagrada Familia".

As for the Ronchamp model....how were the tower tops modeled? For the life of me, I can't seem to figure out what the best approach to carve that shape out is since it does not end in a flat face, but is all rounded up. Thanks for the tips!

[Paul P.]

Maybe now that people can see what can be done in Revit, as Tatlin's examples show (very cool by the way) with making these non-box like building they can get on and learn how to use Revit and produce some examples to for us to see.

Paul.

[AP23]

The NURBS import is very cool, but i haven't had any luck with it. The import and pick by face is not a problem but the computers hangs terribly. I keep getting the "Revit not responding" message from windows. I have a P4 2.8 Ghz with 1 GB memory. I'm not sure if I have to crank up the memory or get a new processor. Have you guys been having the same problem.

Here is an example of the Nurbs Import i have been experimenting with. It is a surface made out of four nurbs curves and lofted in Rhino. Can you make compound walls, roofs and floors with the surface in a manner that when you cut through it, it shows the different layers? Also I experience mapping problems with brick. Surface turns into a on red mep and is not segmented

Furthermore, the curtain wall by face tool is also very cool, but I have lots of gaps, because the glass panels obviously don't bend. Making a glass curved family and curved mullion family would be the solution, however, each glass panel and mullion have a different curve so it would be almost impossible to calculate each curve and make hundreds of different types. Making the panels smaller is another option.

[ejburrell67787]

I've started a tread previously about the import problems. When I import a complex geometry into Revit, my computer freezes. I have challenge some of you to import the file, but no one could have worked with it. So, I'm very curious on what type of organic forms people here are talking about that do import successfully into Revit.

I challenge anyone to make roof and facade out of the model. The model is completely split up into separated meshes representing parts of the facade, roofs, windows etc. so theoretically you dont have to do anything. Just do a roof by face or a curtain wall by face.

I downloaded and imported the file and it slowed everything down in Revit for me also. I deleted all the solid floors and structures and this reduced the dwg file down to 1.4MB. I imported the reduced file and then Revit was as smooth as normal. HOWEVER, the dwg is, as you say, all meshes, and therefore you cannot use any of the pick surface functions to create walls / roofs / curtain walls etc... The only way to do that from this dwg file would be to create new mass elements by tracing around the dwg and then use the pick surface tools to picks surfaces of the newly created mass elements. It is fairly complex looking, but not impossible... the hardest bit would be to work through all the layers of the dwg and all the redundant mesh lines to see where the underlying geometry is!!! :screwy:

[christopher.zoog51272]

Oh boy, A walk down memory lane here. I think I built this model when we were still developing Revit 3.0 and I think it shipped on the Revit 3.0 CD. I do not believe the dataset or images are used in marketing materials or distributed by adsk anymore for various reasons.


It did ship on the 3.0 CD, I found an old burned copy that Chris Manhoney had FedEx'ed me on Feb 23, 2001, because at the time we were still on dial up, and I couldn't wait to download the release :roll:

For fun, I just watched the revit video .......bom bom bom bom ;)

Anyway, It was a great model, and I had fun rendering it back in the day.

-Z

[hand471037]

Anyway, It was a great model, and I had fun rendering it back in the day.

Heck, I still use it for test renderings all the time when I need a model. That and the apartment building I did that I used for my AU class.

The tower tops are an in-place family, made of a Sweep for the curved part, and a flat bit at the top that's an Extrusion.

[AP23]

I downloaded and imported the file and it slowed everything down in Revit for me also. I deleted all the solid floors and structures and this reduced the dwg file down to 1.4MB. I imported the reduced file and then Revit was as smooth as normal. HOWEVER, the dwg is, as you say, all meshes, and therefore you cannot use any of the pick surface functions to create walls / roofs / curtain walls etc... The only way to do that from this dwg file would be to create new mass elements by tracing around the dwg and then use the pick surface tools to picks surfaces of the newly created mass elements. It is fairly complex looking, but not impossible... the hardest bit would be to work through all the layers of the dwg and all the redundant mesh lines to see where the underlying geometry is!!! :screwy:


Thanks for trying.

I'm trying to figure out a workflow to design and document complex geometry like that building from, but from scratch. I would probably start off in rhino, model the skin, roof and sloped walls. Slice the model up and import segments into Revit families. The windows could be done in Revit trough in place families but would be very cumbersome. I would have to boolean curved two directions walls. If Revit allows tilted beams, the structure can be done in Revit as well along side with regular horizontal floors, wall partitions and stairs. it seems that these type of building requires a huge amount of time to figure out walk arounds opposed to slicing the geomerty in rhino and importing it into AutoCAD for documentation. So, it is interesting to find out when to use what tool.

[duncan.hammond]

Sorry to be a pain but can someone point me in the direction of a tutorial on creating a NURBS surface as I can only seem to create a poly mesh using the edge surface command in AutoCad 2006 Please find attached a sketchup model of what I am trying to acheive

[davidwlight]

Sorry to be a pain but can someone point me in the direction of a tutorial on creating a NURBS surface as I can only seem to create a poly mesh using the edge surface command in AutoCad 2006 Please find attached a sketchup model of what I am trying to acheive
Duncan,

Autocad can't create NURB surfaces, although products like Rhino & Max can. Have you tried importing the sketchup model into revit? If you need the splined roof, as you suggest, try exporting the sketchup model as a DWG, then import that into a blank mass family then use this within Revit. Failing that if you have access to Rhino, generate the NURB surface in Rhino & do the same import process as I suggested. You may be able to do the surface in VIZ or MAX as a NURB surface & bring that across, however I have never tried it. As Rhino is based around NURBS you could check these out....

http://www.rhino3d.com/tutorials.htm

[duncan.hammond]

Thanks david you were my next point of call anyway (through exitech). I did try the initial suggestion but only a few of the panels converted into a curtain system. I will try and work out how to do it in Viz although I am very much a novice in that at the moment ( I think I have talked Capita into getting me on a course in a couple of months).
Stop Press - I have just downloaded eval copy of Rhino and got it sorted. It will take a while and some further Revit training to get it tweaked but I am hoping this is the way forward. Thanks again David Work in progress attached

[truevis]

..We also tested 3d printing using this dataset. We still have Zcorp physical models in our office...

So, what is the best method for printing Revit models with a Zcorp 3D printer? If it was easy, you'd think that it would be promoted.

[Scott D Davis]

So, what is the best method for printing Revit models with a Zcorp 3D printer? If it was easy, you'd think that it would be promoted.
Revit>Export SAT>send to Zcorp printer through their software.

[davidwlight]

Thanks david you were my next point of call anyway (through exitech). I did try the initial suggestion but only a few of the panels converted into a curtain system. I will try and work out how to do it in Viz although I am very much a novice in that at the moment ( I think I have talked Capita into getting me on a course in a couple of months).
Stop Press - I have just downloaded eval copy of Rhino and got it sorted. It will take a while and some further Revit training to get it tweaked but I am hoping this is the way forward. Thanks again David Work in progress attached
Glade to be of assistance.....its worth having a look at formz as well....however I don't think the trial version will allow you to export or save, also its more expensive than rhino...but it is a dame fine app.

regards

[cwentworth]

It is a lot of fun! You output it as a DWG Polymesh. Then bring it into AutoCAD and ouput it as a VRML then bring it into ZPrint and if it's ok then your done. If it has bad faces you need to clean it up in a mesh editor like Magics. I have 3 Contex (ZCorp) printers. I've done a few revit models on them. Let me know if you'd like me to look at your data.

Chris
3DRP

[jcyr]

The reason a walk-through path uses nurbs is that it is part of Accurender which is embedded into Revit. Accurender is from Robert McNeel & Associates the maker of Rhinoceros which is one of the best NURBS based modelers out there. If you want to do complex organic forms use Rhinoceros and use Revit for the 98% plus buildings that people can afford to build. You can model complex parts in Rhinoceros or other free form modelers and import them into Revit.

The model of Ronchamp was very painful to complete and is essentially carved using Revit's simple modeling tools. It was done as a personal challenge by someone who is very talented using 3D tools. It became a marketing tool in Revit's early years. No one would seriously use Revit to create such a model.