THE ARCHITECTURE OF 3D PRINTING - 07 STL EXPORT FROM REVIT

[Stefania Dinea 101]

I am Stefania Dinea, an architect who mixes 3D printing, VR, parametric design and blogging daily and I will share some of my 3D printing tips & tricks with you. This series is my overview about the process and my work-around. Please feel free to comment and add. 

 

PREVIOUS POST:

THE ARCHITECTURE OF 3D PRINTING - 01 TOPOGRAPHY

THE ARCHITECTURE OF 3D PRINTING - 02 MASSING

THE ARCHITECTURE OF 3D PRINTING - 03 TOLERANCES AND SNUG FIT

THE ARCHITECTURE OF 3D PRINTING - 04 ENTOURAGE

THE ARCHITECTURE OF 3D PRINTING - 05 HIGH RESOLUTION BUILDING FACADES

THE ARCHITECTURE OF 3D PRINTING - 06 INTERIOR DESIGN

 

7        STL EXPORT FROM REVIT

 

The most confusing thing that you need to have covered is exporting the stl. Starting with revit 2018.3 Revit had the stl export as an add-in, however for those of you who work in older versions here is how you go about it. 

Go to the X (the blue and white one)-  to open Autodesk app store

Search for stl and the following apps will appear:

You will want STL exporter version x – corresponding to the version of Revit you own.

Remember it will export all elements in the view – if you don't want to see something – hide in view, and if you want to see 1 element of out 1000, you can isolate in view.

 

In the export settings, pay attention to the units the export is done in, that will play a major role when scaling in cura –and it will help you see where you are at.  For the site I will use meters. Also, it will be good to be constant, if you start with meters, you need to keep it like that for the whole project so you don't get confused.

CURA

1.      SCALE

We all know in architecture scale plays a big role – therefore this is another aspect that you need to pay attention to.

 

Taking alternative 1 into consideration and our topography/massing examples we know the following:

Our example file in x-y is 87x88 m

 

I have exported, as I said using meter units instead of mm

And in cura we will see the following:

 

Also, one can use online scale converters such as:

http://www.scalemodelersworld.com/online-scale-converter-tool.html

 

 

 

We therefore can conclude that our model is in 1:1000 scale at 100% in cura

And 200% will take us to 1:500

However, when we talk about site plans, a 1:400 would be desired therefore a 250% scale in cura would be ideal, however the site is a little too big for that, so, we will go back to revit and readjust with the section box.

 

But first, you can use the scale calculator to see what maximum sizes you would need.

 

 

So rescaling the section box, you get to print in scale 1:400 and fit in the building plate.

 

 

This is all for this post, I am slowly moving into the Cura tips and tricks (better say my tips and tricks) - as usual feel free to say what works for you, what is your work-around in your main software or in Revit. Also guys and girls, what are your expectations for the summer - should I keep posting or should I take a break until august? up to you!

 

NEXT ON THIS SERIES:

08 SINGLE EXTRUSION

Edited August 3, 2018 by Stefania Dinea

[SandervG 1,521]

Great stuff, a basic need but we all need STLs! Is there any difference between STL and STL ascii? The latter has some more model information I believe and the file will be bigger, but is there a noticeable difference in your model as a user too?

[Stefania Dinea 101]

@SandervG - I usually export in binary - never questioned this system since it was never really explained, from other software i control the number of polygonson export, but Revit does not have this option -- buhu!

[nallath 1,124]

STL is one of those weird formats where there is a difference between ASCII and Binary.
Binary is "simple" and much smaller (due to less overhead). It basically makes a list of 3 numbers "wide" and number of triangles long. The first point is X, the second point is Y and the third point is the Z. Repeat this until you have all the polygons

The Ascii version of STL does something different. It provides a "human readable" version of the file that looks like

facet normal ni nj nk
    outer loop
        vertex v1x v1y v1z
        vertex v2x v2y v2z
        vertex v3x v3y v3z
    endloop
endfacet

But as you can already see, it suddenly is supported (at least, technically) to have a single face that isn't a triangle. Why the hell someone decided to have a completely different functionality set based on how you stored it is beyond me (it's also why the only reason that we use STL is because everyone uses it, not because it's actually good)

[Alex L 29]

For comparison, this is what ArchiCAD gives you:

[yttrium 0]

I would like to add:
For a quite new software. Simple exporting is not what s actually needed here... the outcome is usually useless and heavy data.
A specific 3D-PRINT-EXPORT should fuse all and everything into one single solid, no internal cavities, no single surfaces.
For professional use i even would want to have a adjustable algorithm for adding thickness to overly thin stuctures in regard of printing in scale. actually this is what free software already provides.
Even with this expensive piece of software, one still has to go to the freeware meshmixer in order to "repair/make-it-printable" data.

[nallath 1,124]

Expensive? You can download Cura for free 😉

[yttrium 0]

37 minutes ago, nallath said:

Expensive? You can download Cura for free 😉

I am talking about Autodesc Revit...

[Stefania Dinea 101]

@yttrium you are not the first/only one expecting this from Autodesk - I can say that this is the main reason this blog is here, that so much time has passed and no one click solution was provided. I started printing about 4 years ago and at that time Revit was still my no. 1 software to go to - I soon changed to Rhino and became more confident in using that software and all it’s visual programing plug-ins to handle massive amount of revit data in regards to 3D printing — the results are that working with revit is time consuming in regards to 3d printing and it will be a never ending story until someone does something about it. This blog is indeed a little light in algoritms since its purpose was to be accesible to everyone , not only people with know how in more than one software. With this being said I would just like to mention again - you are not the only one with these wishes - we, all revit users ,want the same thing in regards to this topic. 

 

 

Edited July 4, 2019 by Stefania Dinea