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. in the kingdom....and 3 days later I quit that job.