Martin Wattenberg:
Mark and Scott have chosen the same subject (physics-inspired differential equations) but have produced such contrasting results! It is like looking at two nudes by different artists. Scott's work is pure and precise with an Edward Weston "f/64" level of detail. Mark is like an artist who uses layers and layers of paint to emphasize motion and overall form. Is there a parallel contrast in the source code? Perhaps. Mark's code relies on layers of "library" code. Scott's program pivots on the exact values of a few variables.

I like the color scheme Mark chose; also I liked it when his applet switched from drawing to erasing. One thing I noticed is that seeing the source code did not add anything to my view of his piece; I feel like all the meaning is contained in what I see when the applet runs. ...whether the source code changes the view of the piece is certainly not intrinsically bad or good. It's an especially interesting dimension to me because, unlike other visual artists, software artists necessarily write a purely verbal description of their work.

Scott Snibbe:
Mark Napier's piece immediately has the feeling of a painting. Even before the painterly surface develops or the program is launched, one can see in the code the history of changing the constants of the simulation to achieve the artist's purpose, like the working and re-working of layers on a canvas. When the program starts, this painterly aspect is confirmed. The deliberate choices of color and composition become apparent -- 3 points connected, off-center in green and turquoise with the attractor slightly above. The assymetry of the composition immediately expresses the decisions of the artist.

The work combines dynamics and drawing -- there is a physical interaction with the spring, but the results of your actions have consequences. The traces of the bars are etched into the canvas. The ultimate effect is ghostly and attention flips from the dynamic bars to the static painting. Flipping from positive to negative space adds surprise to the piece, and also assures that the work is perpetual -- the canvas cannot be filled. The choices of simulation parameters result in a spring that isn't quite controllable. Small changes can have large effects and the interaction can feel like trying to coax a cat. I also noticed that when I placed another window on top of the canvas the piece sped up considerably -- anxiously asking for attention. Finally, Mark makes use of the canvas as a stage -- the spring can go completely offstage for long periods, then suddenly re-appear, coming back into view.

I would be quite interested in seeing a few judicious comments in the other code. Mark's was quite understandable to me, since I have done lots of simulation, though his integration is different that I am used to -- it would be interesting to see how Mark thinks about the simulation -- there are many different conceptual approaches to moving from analytical equations to discrete simulations.

Martin Wattenberg:
I like Brad's method of using code to comment on code, so I made an applet to comment on Mark and Scott's applets. It combines Scott's geometry and interactivity with Mark's rendering style.

[Mark: Cool. I like the way the lines fade in gradually. It's amazing to me how much of a difference translucency makes. I find that I really need that soft-edged quality and subtle color gradations to enjoy a work visually. Unfortunately it's not an easy quality to generate in Java 1.1 or 1.2. I immediately got the connection between this work and the originals, but still found it to be engaging and surprising on it's own terms.]

John Klima:
nice smooth physics! rigorous object-oriented approach, i'm usually far more lazy when it comes to my classes. mark mentions translucency and how he needs "that soft-edged quality and subtle color gradations to enjoy a work visually." i'd like to question this notion. naturally personal taste applies here, but i think the "warm and fuzzy" is on the verge of becoming a bona fide cliche of the computer-generated image. we see it in golan's piece as well, with the fade in/out of the countries on the mouse-over, and it's an attribute of almost every high-design web site, especially the flash- driven variety. indeed its "easy on the eyes" but perhaps that's what makes it too much like "candy" for my tastes. just as in traditional drawing media, i've always favored the strong, confident line over the smudgy, shaded technique.

Golan Levin:
Mark merges the inherent chaos of a Double Pendulum with the noisy personality of an Euler integrator, to great effect. There are some nice patterns to be found in the code: iteration, simulation, a delicately hand-rolled Bresenham's line, alpha blending. I think the Javascript reload is forceful and a little risky: having been burned one too many times by browsers, I might have tried to find a way to clear the scene from within the applet code itself. It doesn't matter. The piece has good staying power. Run it overnight.