Sunday, August 10, 2014

Modelling The Finnish Drum

One of the highlights of being BIMTROUBLEMAKER is that i occasionally get emails from readers asking me for help in figuring out how to generate forms.  A few weeks back, I got an email asking about how to make this in Revit:





Not a lot to work with, but enough.  I get it, a column that hugs the face of a drum and rises at an angle.  Simple.  I did it as a conceptual mass to make my life quick and easy.  If this was for a real project, I would have done it as a "Structural Column" family, which is more or less the same steps, except starting with a different template.

So first, lets make the section outline of the column by constraining 2 arcs to the left and right of a reference plane.  This will allow for better control of the angle as this column sweeps around:

I save that profile and nest it into a new family.  This new family has several reference points stacked up and evenly spaced.  The distances are controlled by the overall height of the column.  Each reference point acts as a host for the profile I've created.  Additionally, each reference point's rotation parameter is linked to the angle of the desired column lean.


The parameters involved:



Select all the linework and hit CREATE FORM:


After making a dummy version of the building form, I insert the column and copy/rotate it around:


Annnnnd.... I'm done in less time than it took the dude to right me the original email.





The finished file can be downloaded here:
https://drive.google.com/file/d/0B101ixgLlSGXN29ITHBLV29MQ0E/edit?usp=sharing

Sometimes it feels like I am saving the world, one family at a time.

If you got a problem and need some help, contact our global ministry at bimtroublemaker@gmail.com

Sunday, July 27, 2014

Modelling MBS 2: The Boat


I came to Singapore in 2007 to work on the Marina Bay Sands project.  The building was designed by Moshe Safdie and Associates.  Moshe assembled a very talented and dedicated team of designers to put all the pieces together.  The design for the forms was done in late 2006 into 2007 using Rhino, 3D Max and Maya.  At the time, Revit had yet to introduce the conceptual massing environment.  I've often wondered what the process for generating these forms would have been like had it been done using the more recent capabilities of Revit.  So i did some studying...

Let me be clear at the outset that i don't intend to get these exactly right.  I know there was considerable effort, deliberate nuance and extraordinary care that went into the development of this design.  My intention is to use the forms as examples for a lesson in how we can use Revit's conceptual massing in the form-finding process.

Part 2: The Sky Park

Also known as "The Boat on top of the Hotels" or "The Surfboard".  call it what you want, but this guy was simpler to put together than the hotel forms, that's for sure!




So what we have here is an extrusion along a path with a rounded, long nose and an abrupt tush.  Because the extrusion is dynamic at the ends, the profile i use to make the extrusion will need to change in a controlled manner.  This is a really great example of how reporting parameters and adaptive geometry work together.  We can do this.  First thing is to figure out the section we are going to extrude.


looks like half an ellipse to me.  I'll open a new family using the 'Genric Model Adaptive" template.  Then i host half an ellipse on the adaptive point like so:


The "W" and "D" constraints control the line-work of the ellipse.  However there is also a constraint called "Width_R".  This is a reporting parameter tied to the Shape Handle point on right.  This Shape Handle Point is hosted on the same reference plane as the ellipse, and is also constrained to the XY plane.


Let me explain the parameters here:


"Width_Typ" is the typical desired width of the Boat.  Though not directly controlling the profile, this number will be used in a formula to drive the depth of the ellipse as it reduces at the nose and tush.
"Width_R" is the reporting parameter between the Adaptive Point and the Shape Handle Point.  This will directly drive the width of the ellispe.
"W" is the constraint on the width of the ellipse generated by the autosektch dimension when the linework is initially drawn.
"Depth_Typ" is the desired depth of the form in its typical configuration.  This again won't directly drive geometry but is fundamental in the formula for..
"D" which does control the depth of the ellipse but is driven by a formula which will reduce the depth of form at the same rate as it is being reduced in width.

With this done, we can construct the geometry, beginning with the arc for the mid-section.  I'm a fussy guy.  I like to make 2 arcs off of a primary reference plane.  I think this makes it easier to align the geometry i've created when i insert it to the project later.



Next up i will add an inner arc representing 1/2 the width of the form, nest in my profile, and wire up some formulas.


Select my profile and the path and I'm 1/3rd of the way home.


Getting the nose done is a more complex operation.



First I added an ordinary Reference Point to be placed at the end of the center arc.  Upon this point, i hosted half an ellipse and a straight line.


I added constraints related to the width of The Boat and the length of the nose.


I hosted my profile on the straight line and made sure it was at the 0.0 beginning of the line.


Copied it at intervals along the line, decreasing the interval at the end with the final profile at 0.9999


Picked the profiles to create form and voila!



Tip of the nose looks round enough for this exercise


And the boat is starting to come together



Now what about the tush?


This is not a posterior that would excite Sir Mix-A-Lot.  Kind of flat.  To avoid a bunch of Trig while maintaining the parametric disposition of this exercise, I'll just do it as a 3-point curve.  Again i host a reference point at the end of the center arc.  The 3 points shown all have offsets linked to parameters.


Same straight line as at the nose:


Again i spread out my profiles incrementally




And I'm on a boat...




Have some parameters

 Coming together....






Its a big blue watery roll.....

Thursday, July 10, 2014

Modelling MBS 1: The Hotels



I came to Singapore in 2007 to work on the Marina Bay Sands project.  the building was designed by Moshe Safdie and Associates.  Moshe assembled a very talented and dedicated team of designers to put all the pieces together.  The design for the forms was done in late 2006 into 2007 using Rhino, 3D Max and Maya.  At the time, Revit had yet to introduce the conceptual massing environment.  I've often wondered what the process for generating these forms would have been like had it been done using the more recent capabilities of Revit.  So i did some studying...

Let me be clear at the outset that i don't intend to get these exactly right.  I know there was considerable effort, deliberate nuance and extraordinary care that went into the development of this design.  My intention is to use the forms as examples for a lesson in how we can use Revit's conceptual massing in the form-finding process.

Part 1: The Hotels

As you can see from these images, the hotel towers are dynamic and morph in all directions as the rise up.





To try and replicate the geometry, the first thing I did was make a rectangle in the conceptual massing environment with key parameters controlling thickness, left & right offset and the shift from the main axis.  All of these are INSTANCE parameters.


The next step is to take this profile and nest it into a new conceptual mass family containing 4 levels.  Paste the family to all three levels.



After linking parameters to all the profiles, I created the forms, one for the "City" side, one for the "Ocean" side.



And now the fun can begin!  Tweaking the parameters like so:



will yield the following results:





Not bad for a start...but because of the way Revit joins geometry, the top portions of the tower aren't straight.  I don't think Moshe would have settled for such wacky wobbly BS, so lets try another way with an extrusion and some reference points.  Aiming for better control.  First, the profile:


and the parameters:



Nest it into my family and make the forms:



And we are cooking now!  The wacky wobbly is gone!



Now to add some voids to cut the edges.  First i place a reference point on a plane which has been constrained relative to the length of the towers.


I used offsets linked to given dimensions to setout a bunch of other reference points which in turn makes the profiles for cutoff voids.



After making them into voids:


Booyah....




parameter list for the finished product:




and a link to download the family:

https://drive.google.com/file/d/0B101ixgLlSGXbXBfNmd1cHh4V2c/edit?usp=sharing

man... its nice to be behind the wheel again.