ComponenteDevoto_spline-based geometry

 
Revit Architecture 2010 has a new sistem to control geometries: it's about the use of reference points and splines. This topic is very well explored by David Fano in his superb tutorials at DesignReForm
 
1_R2009: chained line vs spline
In revit 2009 it was possible to make splines: these were not parametrical though.
 
 

It is possible indeed neither to draw splines as reference lines, nor to make their geometry associative. On the other hand, a ref. line connecting two intersections of reference planes create an associative contstraint.

This associative reference goemtry is undoubtely useful, but it does not allow every kind of operation. For instance, they cannot be path for a sweep (while spline -smooth/polyline) can. Moreover, the ref line is fully driven by ref planes, and it cannot drive itself other geometry -unless constrained enterely with formula.

 

2_R2010: reference points

 Autodesk enhanced Revit 2010 introducing geometry driven by points. It is possible to constrain these entities directly.

It is indeed possible to make a ref geometry vary parametrically on a spline. Moreover, spline can itself drive ref. points, each of them "carrying" his own ref. plane (whose normal is the tangent to spline passing for that point).

This tool is extremely powerful.

 

3_Spline in ComponenteDevoto

I would like to build up a parametric model which has all his elemets driven by the same geometry: i find that this geometry could be a spline. 

Elemets in my project which could be spline-based are: 

  1. RPG diffusing system and its own structure
  2. Basement and sitting system
  3. Structural Box connecting basement and RPGs

At First, i've modeled a spline in R2010.

Althought constraints and dimensions are hidden in this view, This spline is made of 6 lines, each of them 30.8cm long (one schroeder profile module). We clearly see difference between driving points (bigger) and driven points (smaller, they will host wooden sheet family).

In fact, this spline is a chain of six smaller splines, each of them connecting 2 points only (these splines are straight indeed). Driven points are constrained to driving points.

The variation consists in changing the agle between a segment and the other. Each Driving point indeed has both its x and y position constraned by a formula.

As i was saying, driven points are hosting a family of wooden sheet, whose instance parameter are at present just inserted manually. 

I've made this model manually, but i wish i could write a routine in order to do it better and faster, controlling the number of rpg modules as well. 

In this way, Variations are associative of course.

What i need now is to build up a model which has this spline geometry including sitting and contructive system. For instance, i need to make a wooden "rail" which has holes in the same position of wooden sheets (see my constructive system).

I would really like to henance my model and build up a real parametric model.