Importing revit - worth the trouble?

[heni30]

I'm emailing an architectural studio about doing renderings and they do everything in Revit.

 

Is it worth the hassle to mess with their models? I would have no control of Revit production at their end.

 

I have zero experience with Revit.

 

Some people will not use 3rd party models and insist on modeling from scratch in Max.

 

Is it worth the trouble to install Revit, learn it, then go back and forth dealing with importing issues. Then have to fix/organize geometry and re-map?

 

Is using an imperfect import as a guide/template to model in Max from scratch an option?

 

Thanks!

[khaledbou]

Why would you model it from scratch? do you want to completely retopo their model? but what for?

If your job is to make only the renders than in my opinion tell them to send you an exported FBX file from Revit, load it to Max, place your cameras, setup a lighting, and do some test renders with override grey material, if you spot issues in some part of the model you can always fix them by poly-modeling or replace them individually not the whole model, plus if you wish to add details (chamfers, imperfections, subdivisions) do it only to some elements that will appear in the camera view, and just ignore everything else even if the geometry is chaotic! if it's not seen in the cameras than its fine you don't want to be perfectionist.

[Corey Beaulieu]

I wouldn't say there are all that many issues importing Revit into Max. At any rate it's faster for most projects than to model from scratch.

 

I use FBX to import and then I manually collapse by name (Revit names like items tagging with a unique number at the end). This collapse will often take 30k objects down to 60 or so. Revit has issues with scale on import (it's probably me), but usually all objects consider themselves 1200% so I normally have to use an xform to get materials to map at reasonable sizes. As a last effort I re-org the layers and delete the Helpers leftover.

 

The only thing to look out for is that things like Railings tend to be parented on import so you need to make sure they don't jump while collapsing. For all of the other objects you can select and collapse using the Scene Explorer and you Geometry hidden.

 

That's how I do it anyway. It goes fast. Might take an hour or so on the high side.

[heni30]

Thanks! Just the kind of feedback I was looking for.

 

I told my contact to send me one of their models to test. He mentioned they have been doing revit renderings.

 

Will their rvt materials come into max with the fbx?

 

I guess I read another post about importing un-optimized large cumbersome files and it made me a little wary.

Edited March 1, 2018 by heni30

[Corey Beaulieu]

The FBX typically tries to setup your scene in Mental Ray so don't count on that working out. Never received anything from a Vray file, but I suppose anything is possible.

 

Generally speaking, the client will think it works smoother than it does, but largely that is a discount towards how much effort goes into the images we make.

 

Long and short is that it's a great start, use what you can, but nothing free is easy nor is easy, free.

[heni30]

Installed Revit trial, downloaded sample file, opened and exported as fbx with no problems.

 

Now I just have to examine all geometry (it's a residence - individual window frame, glass and sill are all one object).

 

Pretty straightforward.....until you get the model from hell.....

 

Do you give a discount when you get a .rvt model? In an older thread someone said they would charge extra if they had to use the client's model.

Edited March 2, 2018 by heni30

[Corey Beaulieu]

One positive on that situation you mention with Window Glass and Mullions being combined is that more often than not, Max will create a multi-sub material for those objects and you can either replace the materials on that level or select by ID and detach.

 

On other word of warning, as is true with most any import, curved objects fail. Max just approximates that geometry differently so they often will be garbage. Fortunately that is a rare occurrence and can be easily remodeled. I often just delete the side and top faces and extrude edges and cap for Mullion type geometry and start from scratch on the more unique. (if that makes sense)

[Corey Beaulieu]

....and no on the discount. What the client gets is a better image for not losing hours to the modelling. Well... Maybe, because it would be typical to charge more when a model must be made from scratch. The whole thing is line item. If you give 3D models, then I can estimate a lower hours effort and the whole pricing structure comes down, but is that a discount? I think it's all part of pricing on effort.

[heni30]

Thanks for the info, Corey

 

Actually he sent me some of their revit renderings and they really are very adequate. They're just kind of boring - missing that final bling/sparkle. So I might be doing just that for them - final Photoshop enhancement adding entourage and finishing touches. With so much work being done in-house these days it seems like there'd be a demand for that kind of work.

[Scott Schroeder]

On export from Revit, exporting as a DWG will give you much cleaner curved geometry. You will get what you expect from Revit to Max. Say an 8 sided cylinder will look like an 8 sided cylinder with the DWG workflow. Not like the FBX way where it appears to be an 8 sided cylinder, but it has 50,000 random verts.

 

The downside to DWG is now you have to work with the lovely autocad blocks it likes to tie to each object and you will get each individual object on import which takes a bit more time to organize and clean. Any of the dwg block cleaner scripts out there do work well, but as Corey mentioned, watch out for curtain wall mullions. Those things jump around if you are not careful when cleaning them.

 

Revit's units default to feet, so keep that in mind. If you are linking an FBX file into your scene, there is a bug in Max 16,17 (untested in 18) that no matter what your FBX's units are set to or no matter what your Max scene units are set to, linking the FBX always scales your geometry to centimeters. It's the dumbest bug I have ever scene and Autodesk flat out refused to fix it.

 

As Revit goes, the bigger the project in Revit the better chance there is for garbage geometry. This whole workflow carries the yyyuuugggeee assumption that the person doing the Revit knows what they are doing and will provide you a 3D capable export. In our office, we rarely use Revit out of the box as our Revit teams are just not working with going to 3D in mind, nor should they be. We end up having to add all of the extra details that it makes more sense for us to just work in parallel with the Revit side and develop our own models. But as I said, our Revit teams are more concerned with construction docs than 3D. The projects that we have currently using Enscape for preliminary white model views, those are a bit more usable for us Max people as the Revit teams are thinking in 3D now.

[Francisco Penaloza]

REVIT to 3D Max workflow is so messy that nobody will believe that they are under the same company. Even with FBX, a file format created by Autodesk and still, they have issues.

 

If you are working with Max 2018 the FBX scale problem is gone, finally!!!

Now when importing REVIT FBX they will come as Autodesk materials, those are not V-Ray compatible and you'll need to pay for a material converter.

Now the only one that I know breaks the material instancing so, after trying many works around I just decided to erase all materials and textures and place them as I need for the what will be visible in rendering, is faster for me than trying to fix and repair already low-quality materials and textures. Default REVIT textures are just nasty, and Autodesk just fill up your HHD with three version of it, it is just ridiculous.

 

Scott is right when comparing the DWG with FBX regarding mesh quality, but if the project is very large, 3D Max will just fall to its knees trying to import the file with many objects, so as with everything there is not a magic solution.

 

I think that learning some basic of REVIT would be good for you as professional, but depending on the project the files can get so complex and full of linked files, it is way faster to fix them in MAX than trying to fix them inside REVIT.

 

REVIT has a different mentality regarding what the 3D Model is for, it is not to look pretty is to get information out if it. so if you try to make a wall join nicely and fit the ceiling grid to match your roof panel, you will disjoint connections and overlap areas that will pop warning inside of REVIT and mess other connected areas.

 

Just try to link/import you FBX by materials or families then overwrite the materials or try some material converter and see what workflow work better for you.

Rebuilding from scratch it does not mean the best option unless you have a lot of time.

 

Also as mentioned by Scott, Enscape and lumion is the best thing that happened to REVIT user, now they finally can see with their own eyes how crapy their 'ready to render' models are.

I've how designers that now use Enscape or Lumion can now instantly see what is not working and fix it before it is too late.

[Justin Hunt]

Importing by Material is really a bad idea, mainly because it relies on proper material assignment in Revit. If its not done right in Revit and you bring it into Max (by Material) there is a very high chance that parts of the model that should not be combined will be. In other words if the Generic material is applied to some window frames, maybe a floor and then some random massing, ALL those will be combined as one in Max.

 

Importing by Family Type is far safer and combines the model in a more logical manner. All the material as still brought and assigned as per Revit.

 

You can import the Revit file directly into Max, so no need to ask for a FBX file. Max will do the conversion for you. The only problem I have come across is sometime trying to bring in a Revit 2017 model into Max 2018 fails. It will come into Max2017 though.

 

As for converting Revit materials to Vray. Vrays converter still doesn't convert Autodesk materials. As a work around I have tweaked Max's scene converter to convert all materials to Standard materials then I run Vrays scene converter to Vray materials. or you could use a paid script which works quite well too.

[Scott Schroeder]

You can import pretty large scenes from Revit. We're importing large size arenas fairly quickly. The key is to work with your Revit person and tell them exactly what you need turned on/off for your imports. Revit items like plumbing will absolutely kill your imports and you never need it for rendering. Railings are another no-no to import. It's much faster and more economical to recreate these with Rail Clone. If you need mechanical or structural from Revit, do those as separate imports, clean them in separate files, then merge or xref those into your main scene.

 

You don't always need to import your Revit in one shot. You can do it with multiple files.

 

I would crap a golden brick if Autodesk could have Revit imports be split out by levels as well. Say for example, currently if you combine by category, you get all of your walls as one object for all 15 floors. If you could tell Revit to combine by category AND level (or workset), you'd get all of your walls as one object for just the first floor, second floor, etc.

 

Architects may not want to release the central Revit file to you, so it's a good idea to get an FBX/DWG workflow down. But yes, if it is possible to get access to the Revit file it is far easier to import that using the Revit Link. You can always bind the link afterwards to get normal geometry in your scene.