Mike Stay has already mentioned two factors: 1. cost (dollars) of the "printer" itself, and 2. cost (learning curve) of writing the "input". Two other factors are: 3. resolution, 4. material. With respect to resolution, there were dot matrix printers before the XGP. What made the XGP so impressive was that its 200 d.p.i. (?) resolution finally reached the threshold of the individual dots being effectively invisible at standard viewing distance. Now compare George Hart's solids and surfaces that he posted a link to, a few days ago. They're very impressive constructions, but the rasterization and the "ooze" still makes an unfortunate first impression. That machine is a DECWriter, not an XGP. With respect to material, many 3D objects that people want to make are not suitable when rendered in low-temperature melting plastic. Again, this is a significant difference with the 2D world. Black toner on white paper satisfied a much larger fraction of the initial demand. Subtractive technologies (machining, more or less) have ruled the manufacture of 3D objects for the last 150 years. Before that, displacement technologies (forging, casting) were dominant. Additive technologies (earlier forms include welding and glueing) have always been an adjunct to the main event. When it comes to resolution, the precision of a modern ink-jet (or laser) printer is an extraordinary outlier among its relatives in additive technology. I too have high hopes for additive methods. But there's a long way to go yet. - John On Thu, Aug 18, 2011 at 1:38 PM, Henry Baker<hbaker1@pipeline.com> wrote:
I don't recall the exact date that the XGP showed up at MIT's Project Mac, but I think it was the very early 1970's. ...
One of the important steps along the way was the development of Knuth's TeX, which subsequently became the standard for mathematical publishing -- where it remains today.
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Fast forward to 2011. 3D printers exist, but don't appear to have generated the same excitement as the original XGP. I'm not sure quite why, because a 3D printer is sooo much cooler than the XGP ever was. Maybe these printers are too expensive; maybe they're too slow; maybe they're too hard to access.
What is missing that would make the 3D printer today as exciting as the XGP was in the early 1970's ?
Does Knuth (or a Knuth-wannabe) have to come up with 3D TeX ?