Chinese New Year

Hooray...Singapore is closed for a week!  I'm going on vacation...

enough already....

Spring is in the Air

I have heard that you can model springs in REVIT and had seen some images of them.  So i decided to figure out how.  In some ways, BUILDZ kind of beat me to the punch with the posts on helixes, which are essentially the same thing...but i was attacking the problem from a different direction...because i believe that anything worth building is worth over-building!  Links to both the models shown here are at the bottom of this post....

First, I created half a coil using a parameter driven reference arc with lofted circular profiles as such:

Then I nested the arc into another family, hosted on a rotating reference plane so it would tilt in elevation.  This is important to note for later because the radius of my coil segment is no longer equal to the desired radius of my spring:

Now, I nest my rotated coil into a third and final family, where i create as levels as i want.  Each coil of the spring is located on its own level and rotated 180 from the half coil directly below.

The distance between coils and the desired spring radius drives the coil radius and rotation and is shown in the formulas.

and i am now falling asleep because this form is sooooooo boring!

So I decided to try again, but this time I added some monkey-business.

Going back to the creation of the initial coil, I figured that I could use an ellipse for the loft path.  To make the piece more dynamic, I added a pair of elliptical profiles hosted on reference points, to the path.

This is the parameter list for the final model.  Similar to the simple curve except for the "Start Profile" and "End Profile" parameters which control the position of the refrenece planes along the loft.  I also programmed in a "Transition PCT" so the end lengths could be controlled as a percentage of their allowable length.

And now the form gets a bit more interesting...

With a bit more work, i could probably sort out how to expand the springs as they get taller.  Something to throw in the pile for later.

The Round Spring model can be found here:

Spring Circular.RFA

The Elliptical Spring model is here: 

Spring Elliptical.RFA

Helix Methods at BUILDZ:

Helix v.1

Helix v.2

Reader Email: Millenium Hilton WTF?

I got this email yesterday, and i thought it would be worth posting up.  If you send me a good question, I'll post your email too!  And if its a really good question, I'll send you a bag of tasty Peppridge Farm cookies to boot!


Hi Troublemaker,

I am 31 years old currently working here in Dubai as CAD Technician.

I am hoping to learn Revit as much as I can. I browse the internet for some tutorials and I am happy that I can little by little learn from it.

I have seen in YouTube the sample of your Massing Study for the Millenium Hilton. Since the pacing is very fast and its hard for me to follow how did you do it, i would like to ask a favor, I am just trying for my own self study, to have a copy of your Revit file for me to review. By the way I am just new in using a Revit and I find it interesting to learn. I am more on AutoCAD and Microstation only.
Best regards and more power,

Allan

--------
Hi Allan,
I am happy to help you out, not too long ago, I was a complete newbie at this too...I had to figure out alot of it on my own, which may or may not have been a bad thing.I can’t share the whole model, but i will tell you what i did, and i'll send you the head piece to take a look at.

 LINK TO MILLENIUM HEAD MASS.RFA
When I model, I usually create several 2d families that i use as profiles for my work. So the crown is basically one nested 2d family, copied onto 3 levels, with it’s parameters linked into new parameters in the host family. I then picked all 3 profiles and hit 'create form'….voila!

The body of the tower was similar. I made one 2d family for the base level, one for the top of the taper, and another for the ordinary rectangle at the top. The base profile was toughest because i had to figure out how to control the curvature. I ended up creating a curve that i controlled using dimensioned reference points.

There are a couple of key things to keep in mind.

1) If you use 2d families as profiles, it helps to host them on a reference plane that moves, rather than trying to dimension them vertically. Alternately you can use the offset control, but I stay away from that for no reason other than preference.

2) Think the whole thing out ahead of time. Break the form down to its constituent parts and the model will get alot easier. You will then see what needs to transform and what doesn't. With that understood, figuring out which parameters will have to be linked between the nest and the host will be a snap.

The bulk of what you are seeing in Massing Study for the Millenium Hilton video is me placing these profiles in the host family and linking the parameters.

Start small, start easy...find a simple building near you and just figure out how to model the mass....That’s what I did to learn Revit.
Thanks for writing.
TBT

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...

___________________________________

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.