The BIM Yellow Pages

This is cool.

A big list of people on he web who blog about BIM and Revit:

http://sites.google.com/site/revitblogdirectory/

Brought to you by this guy:

http://whatrevitwants.blogspot.com/

I am gonna go home tonight and pray to the BIM Fairy that i can get on that list..

Using Parametric Curves to Drive Surface Geometry

One of my purposes of this blog is to post up the work I did while discovering how to effectively harness the parametric modelling capabilities of Revit.

At first, I had a lot of trouble figuring out the difference between 'Instance' versus 'Type' parameters and where you would use what.  This is an exercise where I figured out the difference and how to imbed "Type" Parameters in a model.

First, I laid out some refrence points at random.  Each point was linked to some dimensions and then I drew a curve through the points.  All of the parameter here are 'Type' and created a few different types with the points in different places.  This model was saved and would become a NESTED PROFILE.

Then loaded the curve family (aka THE NESTED PROFILE) into a new conceptual mass model (aka THE HOST), one on each level.  The important thing I figured out here was how to apply a 'Label' to each NEST, using the panel in the top left corner.  This allows me to change the NESTED PROFILE for any level within the HOST family.

I select all my NESTED PROFILES and hit the CREATE FORM button and voila!  I get something like this....

But that form in and of itself is not very interesting, so i go to the Family Types panel and I can see all my labels lined out and ready to be adjusted.  In the original NESTED PROFILE model, I set up the different Types which controls the points which drive the form.  If i want more NESTED PROFILE types, I can set them up from the project browser, just like with any other family.

And so with this meshugas behind me, I was able to get into something like this:

Conceptually, this process opens many doors in generating complex forms.  I use nested profiles quite often my work.  The Millenium Hilton model was done this way and an understanding of these principals underpins the Parametric Sightline work.

Parametric Stadium Seating Bowl Design in Revit

December 2008 I walked out of AU with two goals in mind:

1) To learn Revit, because I'd never used it.

2) To use Revit to build a Stadium Sightline Design Tool.

I flew back to Thailand and, settling into what became a year-long break, got down to business...13 months, 2 trips back to the US, 2 computers, 2 releases of Revit, and 4 South East Asian cities later, this is what I came up with.

Part 1: The Grid

Understanding the principles of seating bowl grid geometry is one thing, programming a grid family is a much tougher nut to crack...but i figured it out.

Part 2: The Section

3 decades ago (1997, actually) I learned about C-values, Focal Distances and all that. Putting it together here though required both digging into trig fundamentals and entering a list of parameters as long as my arm.

The Sightline Design Family I developed uses the key variables: C-Value, Distance to First Spectator, Eye Height, Row Width. I also threw in a parameter for Minimum Incremental Distance Between Treads, essentially a rounding factor, which can positively impact construction efficiency.

Creating a section in 3D allowed me to project a preliminary seat count for each structural bay. I have different tool for counting seats more definitively as the design progresses.

Though I only show the seating section as a single mass here, I also have a version which will itemize and schedule each individual piece of precast.  This could be a useful tool for quantity surveys in the later stages of the design.

Part 3: The Bowl

Here I bring both tools together. The model shown took me about 10 minutes to assemble. By linking my sightline section family to the grid, I can cycle through endless bowl options.

There is surely more to investigate; vomitories, disabled platforms, rails and such...Right now, my priority is to look at a method which imports x,y,z points from an Excel spreadsheet. That might make things a bit easier because these families do get a bit heavy.

I owe 2 debts of extreme gratitude to a pair of guys who don't even know I exist.

First is David Baldacchino. I took his class on Fuzzy Math Essentials at AU in 2008. I didn't know anything about Revit Families when I walked in, but knew I would be able to tackle this project when I walked out. I kept the class handout and referenced it often. His blog is here: http://do-u-revit.blogspot.com/

The other is the Revit Family Man. I don't know what became of him because his site has gone a little quiet, but I reviewed his page about Revit Formulae almost every time I sat down: http://revitfamilies.blogspot.com/2005/10/revit-formulae.html

I'd love feedback from others who have been looking at stadium design Revit. I think there is a lot more to be explored, and its fun too!

Revit Curtain Wall Panel By Pattern: OmniGrid Explorations

I am an inquisitive chap and I knew these CURTAIN WALL PANEL BY PATTERN elements existed but i was very uncertain about why they were useful or what i could do with them.

I had some time on my hands and so opened the OmniGrid 4x4.rfa family and played around a bit.

This is what i came out with.

I made a copy of the OmniGrid 4x4.rfa in my own library and begun.  First, I lace a SPLINE THROUGH POINTS, using the reference points already in the template.  Then, draw circles with radius parameters at the ends of the splines.

Loft the circles along the reference line paths.

The forms become more interesting by playing with the radius parameters.

I load the pattern into a CONCEPTUAL MASS FAMILY and then apply it to a surface.  This is Type 1, equal radii at both ends of the splines, with equal lengths for width and height of the pattern.

Here I keep the square pattern spacing, but change the radii at the ends of the splines

Now, start to play with the pattern spacing aspect ratio

And the other direction...

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The swastika/shofar arrangement was interesting (and quite offensive to my mother), but it wasn't giving me the bang for the buck i was looking for.  I could get similar results by mapping a material.

I really want to play with these patterns in 3D and see what happens, so I took a look at a woven arrangement.

Again with the OmniGrid 4x4.rfa, but this time I put in some lines shooting into the Z-Plane and use them to guide my reference splines.  Circles drawn same as before.

Lofting along the splines.

Adjusting the radii to add some drama.

Applying the pattern, with a square spacing arrangement

Square pattern with adjusted radii.

And now i start stretching it around this way...

...and that way...

...and this way....

Gets a little more interesting....but I don't know exactly what i would do with it....A cool woven wall arrangement i suppose.

If you have any ideas, let me know....I'll give it a shot.