Wednesday, October 10, 2012

Rhino to Revit in 47 Easy Steps

I have yet to find the magic button or transfer format which will bring a form generated in Rhino into Revit, and allow for the application of any Revit functionality.  The only ting i have found which works is ingenuity, tenacity and reference points.

So they came to me with this:
And said "lets rationalize the geometry and explore joist spacings and make structural drawings for this roof"

I'm not a Rhino guy...I know that it is a mighty program and plug-ins like grasshopper, salamander & polar bear extend it even further, but I am just not that capable....I knew I could recreate this in Revit faster than learning Rhino.  So here we go.

The first thing to do was bring the model into ACAD and setup the layout circles and cut lines which would govern the geometry in Revit, starting at the topmost form.
You will notice many small circles placed at positive Z values.  These have been placed at the heights described in the original architect's model.  The reason to use circles is that REFERNCE POINTS snap to circles really nicely in Revit.

Also if you look closely, you will see that all the arcs are split up as well. this will make it much easier for me to create the individual surfaces later in the process.

So i bring my completed "Guide-line DWG" into the Revit conceptual massing environment:
With these guidlines in place, recreating the geometry is quite direct.  First i place the REFERENCE POINTS in all the circles, then i select them 3-at-a-time and push the CURVE THROUGH POINTS button.
Then i pick the pairs of lines for the top and bottom of each surface until the roof forms are complete:
The work so far took me an afternoon.

Now that i have the basic geometry in place, I can start using the DIVIDE SURFACE tool to find the joist lines according to whatever spacing is desired:
But if you look closely, its not "perfect".  the design calls for the joists to match 1-for-1 at the ridges of all the roofs, and this most assuredly doesn't:
Playing with both the BELTLINE parameter and the number of segments for a selected divided surface, i could get the arrangement 'perfect'
To cut to the chase, when i bring the form into the project environment, I can start adding structural elements and get to all the juicy good stuff:
It took me about 2 days to input the rest of the base geometry:
 And divide all the surfaces:
 Then i could ship it back to ACAD to generate a DWG file:
And with the wire frame in-place, we could pass the whole arrangement into analysis.
Happiness....joy in the kingdom....and 3 days later I quit that job.


5 comments:

  1. I am very curious to see what resluts you would achieve if you would test out some export settings. I have been playing around with a lot of interoperability between Rhino and Revit and while I haven't utilized some advanced techniques I have been playing with file types. I know that you can export the geometry from Rhino as an ACIS solid (.sat) file format and you can tab to the surface and choose to create a divided surface. It is quite possible that you wouldnt have to go through the whole process of rebuiding the actual geometry.
    Also i would suggest looking into some of the attempts that other Experts have made in this process mainly Nathan Miller from Case. He has wrote an Add-in that will import openNurbs geometry into Revit very cleanly.
    http://wikihelp.autodesk.com/Vasari/enu/Community/Tutorials/Vasari_Talk_-_Design_and_Analysis_Webinars/Session_18%3a_Grasshopper_to_Vasari_Panel_Discussion

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    1. Thanks for the tips on the exporting, i'll keep it in mind for future use. One part of this challenge was rationalizing the form and fixing the connections between some of the roof surfaces. The original Rhino model was still a bit rough. by rebuilding it myslef, i could smooth out the interfaces as needed....sometimes, life is just like that!

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  2. Well done BTM! I'm curious, was there any discussion of the rationale that produced the original shapes? Looks like it might have been a series of cones with other cones subtracted from them?

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  3. Impressive! As a novice Revit user i always dream of using such techniques. At the moment i am still watching countless Revit tutorials. You're the man!

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  4. how did you put the structure on this kingdom? You divided the surface and then... did you do it inside the adaptive family? I will appreciate your answer..

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