Thursday, November 13, 2014


This post is no three of a series on sanitary ware familes.  Last time we modelled a Duravit toilet and bidet.  Here are 2 more of their bidets, which are available as 3d CAD downloads.  Nicely modelled, but as usual they contain seam lines that spoil our 3d shaded views, and of course you can't apply material parameters without resorting to nasty workarounds.  The Puravida also has a missing face.

These two bidets are quite easy to model using the techniques described in the previous post.  The D code is intact, so we could CAD import it into a Revit family.  We would need to separate out the metal fittings so they can pick up a different material for rendering purposes.  (If you are specifying Duravit you probably want to be able to render)  We also need masking regions and symbolic lines in plan & elevation. 

But once we've gone to that much trouble, why not go the extra mile and create native Revit geometry ?  It is possible to assign materials to the CAD layers via Object Styles, assuming the different materials are on different layers.  But really it would be so nice if we could just download well-made Revit families with all the metadata etc all nicely set up.

So here's how I would make the Puravida.  Drop the CAD family into a GMA or massing family.  I find it useful to set Reference Lines to thick red under Object Styles.

Draw the base profile.  You need to change the scale of the views you are working in so the line weights are manageable.  I'm using 1:5.
In a side elevation, create some horizontal reference planes and name them (I just used 1,2,3,4)  Select the base profile and copy multiple.  You have to keep unchecking "constrain" for each new instance.

Now we need to adjust the shape of each profile.  I started by selecting the whole thing (6 segments)  Then I use shift-window to deselect that straight segment at the far left.  Now I can nudge the rest to the right and this will adjust the length without spoiling the smooth tangential curves.

Keep on like this until you have a series of profiles that hug the CAD object quite closely.  Now select them all and "create form".  Looks pretty good.

The void inside the bowl is done in a similar way.  I call this "freehand" work because you are drawing profiles directly on ref planes instead of creating a separate parametric profile family.  I don't have any fixed rules about which method to use, just treat each case on its merits.  This one was definitely much easier with the freehand method.  I don't need the parametrics, just making one fixed shape

Now we can export as SAT and load into Autocad.  Sparing use of the solid fillet command to soften the sharp edges.  You will notice that we have very similar seams to those in the original CAD file, interestingly though most of them disappear later when you explode the geometry back in Revit.

The tap / faucet in the CAD download is quite an interesting shape so I accepted this as a modelling challenge.  The tricky part is in making a transition from a circle to a rectangle with rounded corners.  Ultimately I realised that the key to a smooth transition was having the same number of segments in each profile.  So I just broke the circle into 8 arcs. 

The finished article has 3 parts: extrusion, loft and revolve.  Don't try to make the body all as one loft, the cylindrical portion will never come out quite straight because you are telling Revit to create a continuous curve connecting all the profiles.

I usually use both material parameters and subcategories.  Most of the time the subcategory will control the materials for all the sanitary ware in the project, but just in case one fitting needs to be a different material (gold plated perhaps) ... well you get the idea.

Introducing TIM, my Toilet Information Model.  Nice clean symbolic work in all 3 directions.  The 2d world of orthographic is very important in my view.  By all means let's do away with hard copies, but the conceptual clarity of plans and sections is invaluable.  It helps us to think, to make decisions, to understand problems.  Don't knock 2d.  Be inclusive.  It's a free world.
Oh yes, nearly forgot.  Look how much cleaner my version is than the original CAD download.

Once you have that one made (floor standing) it's relatively simple to backtrack a bit and adapt it to make the wall hung version.  Adjust the profiles, export to SAT again, round the corners, back into Revit, explode ...

After that I went on to make the matching WC.  Same methodology.  Cut across with a sideways void extrusion (like we did in the last post)  Round the edges in Autocad once more.  I don't bother cutting out the bowl for toilets.  Going to show them with the lids down, much simpler.

Turning now to some wash basins.  It turns out that the Happy D basin downloads are in SAT format and can be exploded in Revit.  Whoopee, no need for me to do lots of lofting, just remove the chrome bits and replace them with separate families for easier control.

I decided to use visibility controls to permit swapping of the half pedestal and full pedestal versions.  These are slightly heavyweight families (welterweight ?) so I figured that it was better to combine two in one.

Anyway that was a fun weekend, some time about a year ago I think.  It's embarassing how long it takes to convert some of my work into a presentable format for sharing with the world.  But I do have a day job.  That being so, why am I spending my precious time fiddling with toilet families that should be available for download ?

The short answer is that ... they aren't.  The slightly longer answer ?  I enjoy making good quality content and somewhere deep inside I am kind of hoping that I might eventually motivate others to contribute.  Who knows, Duravit themselves might eventually come tho the party.

I'm going to put some of these families up for download.  I am appealing to the many experienced users out there who follow my blog to test them out and give feedback.  What improvements can you suggest ?  By all means make some changes and send them back.  And please lobby your contacts in the supply chain to make more BIM content available.  In the end it's up to us.


  1. I use similar way to model non parametric families in Revit. Thanks for describing whole process. I've just shared this with my friends. Hats off and thanks again.

  2. Repeating WK's thanks and your generosity in sharing your workflow so painstakingly not just in this post but over the years.

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