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Silly_con

True Voxel, how ?

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I have seen demos that uses true voxels, like the Ken Silverman cavedemo, and voxlap, I wonder how they draw the voxels like cubes, voxels are a group of pixels? they use a function to draw a pxp cube (where p is the number of pixels of a side) ? I''m confused.

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Well technically voxels are "volume elements", sort of like the 3D version of pixels. They aren''t "little cubes", they are merely visualized that way. If your interested in normal voxel visualization, look up "splatting" and related algorithums. Most of those require static volumes. For non-static volumes you could even look at my VSaber (voxel based carving)

http://plaza.ufl.edu/lewey/vsaber/index.html

Hope that answers your question.
-Lewey

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Voxlap uses a basic ray-casting technique (which is why everything looks awful up close). You could quite easily use radiosity or polygons to render voxels. ISTR the makers of Voxlap saying that they didn''t see any advantage to using 3D hardware over a software polygon engine (I guess they got hit hard by bandwidth issues).

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quote:
Original post by fractoid
True volumetric rendering? You''re gonna need one of these...


That''s really cool! If someone could figure out a way of projecting the images without using that rotating screen it would be true 3d imaging. It''s at least a step in the right direction. Notice how the quality of the images are better than the holographic displays they "had" a long time ago in a galaxy far away?

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>If someone could figure out a way of projecting the images
>without using that rotating screen it would be true 3d imaging

What's not "true" with rotating screen?


[edited by - Dmytry on April 6, 2004 8:44:23 AM]

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quote:
Original post by Dmytry
>If someone could figure out a way of projecting the images
>without using that rotating screen it would be true 3d imaging

What''s not "true" with rotating screen?



Well.. It might get painful if you try to stick you hand into it..

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quote:
Original post by Sander
You want something like this then?

IO2 Technology



It''s nice, but it looked like it was a 2d projection on a thin weil of smoke blown up from the projector. The videos and pictures didn''t show the sides of the projector, only from the front. A combination of the two might be cool, but I doub''t the blown smoke would twist fast enough (The other one did 30 "fps").

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It''s not volumetric (still 2D projected into air), it''s not stable (image oscillates a lot), and i hear it makes a lot of noise (more than a Geforce fx!).

Y.

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I doubt there''s one, rigid definition of "true voxels". People''s intuition usually associates it with a 3d grid discretized into cells ("volume elements") which is then visualized in some manner. Funny, that the usual technique of "voxel landscapes" doesn''t really seem to fall into that category.

- Mikko

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But, that 3d grid basically are function of x,y,z .
So,if i'm using function

solid=(z < map[x,y])

it becomes "voxel landscape".

Ken's cave demo just uses 2 heightfields and function
solid = (z < map1[x,y]) || (z > map2[x,y])

Actually i'm not claiming that my landscape are voxels,i'm claiming that my fog are voxels.

edit: i meant that old cave demo where you dig in the cave.

[Edited by - Dmytry on March 5, 2005 12:44:44 PM]

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