3 ms·

This seems a bit like various volume rendering techniques, except with the objects having no transparency (like they would in a typical tomographic reconstructi

This seems a bit like various volume rendering techniques, except with the objects having no transparency (like they would in a typical tomographic reconstruction) See: http://dl.acm.org/citation.cfm?id=378484 http://dl.acm.org/citation.cfm?id=378484 and http://en.wikipedia.org/wiki/Tomographic_reconstruction http://en.wikipedia.org/wiki/Tomographic_reconstruction Very cool for a simple implementation, and considering that the author doesn't appear to have dug deep into existing work.

dualogy 13y ago
Maybe we're using different terms or definitions here --- but for me "volume rendering" is a clearly separate domain from "extract spatial information from 2D imagery"..
- codezero 13y ago
  edit: The above comment https://news.ycombinator.com/item?id=6123729 https://news.ycombinator.com/item?id=6123729 is more correct than I am I think :) Extracting the spatial information is a subset of the same problem, I think. Things like tomographic reconstruction use either multiple rays through the same object or parallel rays through the object at different angles, but this gives density through the object and from that the volume and its shape. If you consider the same problem where you have no density or 100% density, you get the spatial information from multiple 2d objects. I ran into this when playing with IDL ages ago: http://northstar-www.dartmouth.edu/doc/idl/html_6.2/VOXEL_PROJ.html http://northstar-www.dartmouth.edu/doc/idl/html_6.2/VOXEL_PR... and learned about the rest from the references there. I'm not really savvy on the problems though so the math could be totally different and unrelated, but I think you can accomplish the same thing with either method.
  - cameldrv 13y ago
    My research group actually implemented the tomographic approach 14 years ago[1] (and in realtime![2]) It worked pretty well [1] http://www.disp.duke.edu/~dbrady/imaTutorial/papers/science62599.pdf http://www.disp.duke.edu/~dbrady/imaTutorial/papers/science6... [2] http://www.disp.duke.edu/~sfeller/Publications/spiecr76-13.pdf http://www.disp.duke.edu/~sfeller/Publications/spiecr76-13.p...

dualogy 13y ago

Maybe we're using different terms or definitions here --- but for me "volume rendering" is a clearly separate domain from "extract spatial information from 2D imagery"..

codezero 13y ago
edit: The above comment https://news.ycombinator.com/item?id=6123729 https://news.ycombinator.com/item?id=6123729 is more correct than I am I think :) Extracting the spatial information is a subset of the same problem, I think. Things like tomographic reconstruction use either multiple rays through the same object or parallel rays through the object at different angles, but this gives density through the object and from that the volume and its shape. If you consider the same problem where you have no density or 100% density, you get the spatial information from multiple 2d objects. I ran into this when playing with IDL ages ago: http://northstar-www.dartmouth.edu/doc/idl/html_6.2/VOXEL_PROJ.html http://northstar-www.dartmouth.edu/doc/idl/html_6.2/VOXEL_PR... and learned about the rest from the references there. I'm not really savvy on the problems though so the math could be totally different and unrelated, but I think you can accomplish the same thing with either method.
- cameldrv 13y ago
  My research group actually implemented the tomographic approach 14 years ago[1] (and in realtime![2]) It worked pretty well [1] http://www.disp.duke.edu/~dbrady/imaTutorial/papers/science62599.pdf http://www.disp.duke.edu/~dbrady/imaTutorial/papers/science6... [2] http://www.disp.duke.edu/~sfeller/Publications/spiecr76-13.pdf http://www.disp.duke.edu/~sfeller/Publications/spiecr76-13.p...