Team members: Severn Clay-Youman, Nathan King, Daniel Ramirez

Designing for Promiscuity

Because of their speed and efficiency, bicycles may well be the future of transportation in the 21^st Century city. For cycling to reach its full potential in the urban milieu, a locking strategy must be developed that meets the needs of all cyclists. The traditional bicycle rack simultaneously accommodates and explicitly limits the urban cyclist: here you may bring your bike on the sidewalk, here you may park your bike safely, here you are allowed.  It is a familiar type of urbanistic intervention: clearly delineated, appropriately proportioned within the streetscape. It belies, however, the opportunistic nature of urban cycling: rather than a simple replacement for driving a car, cycling fills the gaps between walking, public transportation and driving.

We are proposing a fixture that opportunistically utilizes the existing streetscape.  We are proposing a promiscuous fixture, one that can be attached to a wide range of existing street poles and can accept a wider range of locking methods.  Because it does not require complicated installation, it can meet local demand quickly.  Because it takes up no new real estate, it can serve areas without enough sidewalk space for traditional bicycle racks.

The traditional bicycle locking paradigm draws the line between public utility and the private user at the fixed rack, with the user bringing his or her own chain and lock.  We are proposing to shift this line from the rack to the chain, providing a more flexible fixture that can act as either a chain or a rack, depending on demand.  The cyclist is no longer required to carry a heavy chain with them, and can get by with a small U-lock or motorcycle lock.

I’ve been finishing up my studies the past couple of weeks, so not much work has been done on Pantograph. I have, however, been getting to use Pantograph quite a bit, and have some observations:

• Pantograph is now memory-limited, not cpu-limited. Change is good! The culprit seems to be the Polygon library - my hackish misuse of it is beginning to show, and things aren’t pretty. There don’t seem to be any good clipping libraries out there that do exactly what I need, so I need to write a true 2D geometry core. I’m much more confident in the potential speed of Python, though, so I’m still hoping to match the speed of the 3D geometry functions in the 2D clipping.
• The program needs a Blender-native UI. After using the GTK UI in KDE for the past few months, and from peoples’ hassles trying to install GTK in Windows, I have decided to not fight it and rebuild the UI using the Blender toolkit. One less dependency is a good thing.
• Pantograph is still really buggy. Sorry.

I’ve got two weeks in mid-May to sit down and address the bugs and write the 2D clipping code - stay tuned!

Tamito Kajiyama has written a very comprehensive guide to installing Pantograph in Windows.  Thanks, Tamito!

I’m still working on a few more basic tutorials, and hoping to put some more examples in the gallery.

Some highlights:

• Export an animation to SWF - requires ming-python package
• Export to PDF
• option to re-load last settings
• curve rendering

Enjoy it here!

More from H Diaz Alonso and Florencia Pita’s studio at Pratt:

Thanks to Nathan King for identifying the “Stargate” shader!

The problem with ming was trivial and stupid. Here’s an animation. This is the last piece of 0.4 left to work out, so barring any big bugs the next version of Pantograph should be out some time this weekend.

I’ve been trying to render a larger file with around 160,000 triangles, and there seems to be a memory hole. Things have gotten a lot faster, but it eats up 8GB way too fast.

Pantograph 0.4 is coming along nicely - quite a few features that had been planned for a while have almost reached fruition. Plus, I’ve been able to do a lot of stress-testing with large data-sets, and necessity is a good optimizer. I’ve closed a few huge memory holes, and tightened up a lot of the data structures. Needless to say, the code will need a good laundering after 0.4 - its a mess, and some fundamental paradigms have been shifting.

I’ve been replacing a lot of the lists in Pantograph with sets - it seems I was spending a lot of time removing items from the scene, which can become quite costly when the number of faces is over 100,000.  I’m hoping that sets can squeeze a bit more performance in places where I don’t need ordered sequences.

I’ve got libming (mostly) working - it will make an swf file, but I can’t figure out why its not showing all the frames:

test.swf

Ming won’t do dashed lines, unfortunately (that I can discover). And the Python documentation seems to have been written by accident…

Getting smooth curves:

Since Pantograph is working from a faceted model, you’ll never get true smooth splines (believe me, I’ve been trying to figure out how to do that!).  With some quick work in Inkscape, you can vastly improve things.

After ungrouping the drawing (Shift-Ctrl-G), you will be able to select individual polylines

Hit Ctrl-L (”Simplify Path”) until you are satisfied  with the smoothness of the curve.  If there are multiple overlapping linesyou may need to smooth both.