I love the concept of this web app. The renderer appears to be a true HTML5 canvas based rendered. It was a bit too slow to run on my computer, but I think there is (or will be) a big market for an efficient canvas based renderer for these types of files.
Red areas will have a rougher surface texture than yellow sections.
Anyone who’s operated a 3-D printer knows there is more to it than just quickly designing an idea and pressing “print.” In order to get good parts without errors, artistry is required. A designer needs to balance their design with the machine that is being used, how the part is oriented, and where it’s placed on a build platform. Make the wrong choice and you could spend hours and hundreds of dollars on a part with the 3-D equivalent of a typo.