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Very cool. Anyone know how a sphere (the globe at the end) was printed in a single immersion? Based on what I saw in the video, it seems like it would have to b
by agf 11y ago
Very cool. Anyone know how a sphere (the globe at the end) was printed in a single immersion? Based on what I saw in the video, it seems like it would have to be a different process involving rotating the sphere as it was dipped, rather than the linear motion used for the other objects.
- DanAndersen 11y agoWas the sphere inside the globe framework when it was printed? If it was merely a sphere being immersed, then perhaps a polar projection map would be able to cover all of it.
- alepper 11y agoFrom the paper[1], it sounds like the same linear motion with the film wrapping around to the top: > The sphere is dipped with > its north pole pointing downward. The maximum error on the > northern hemisphere is within 2mm. However, near its south pole > the error is much larger (about 5mm). This is because after the > water surface passes the sphere’s equator, the film gets stretched > largely, and near the south pole the relative angle between the > water surface and the object surface approaches to 180◦, leading > to an ill-posed boundary condition for our simulation (recall > Equation (1), when θ ≈ 180◦). You can see the potential for a similar wraparound even on e.g. the mask dips. [1] http://www.kunzhou.net/2015/hydrographics.pdf http://www.kunzhou.net/2015/hydrographics.pdf
- madaxe_again 11y agoDon't believe so, a single projection with antarctica on the outside and the north pole at the centre would likely work just fine - and they showed it top-down.