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2.11	Video Derived Polyhedra.

~JU;FA	The easiest way to make a polyhedron from a video image is to
sweep  the silhouette  of  an intensity  contour from the program
CRE  (a video
contouring program). The  CRE commands "T" for  take, "C" for  contour
and "αO" for  output contoured image will yield a  disk file suitable
for  input to GEOMED.  Using GEOMED  commands: "βI" will  input a CRE
file and create a face, edge, vertex data structure on the now camera
node that corresponds to the contoured image;
~JA;FA
	0.	TC10αOHAND.CRE		CRE Commands to take, contour and output.
	1.	βIHAND.CRE			GEOMED input from CRE file.
	2.	αC...				Locate a suitable contour body node.
	3.	XSIL <ZMIN> <ZMAX>	Sweep out silouhette polyhedron.

~L0,-200;JUFA
	The CRE program is documented in Stanford A.I. Memo #199, titled
`Image Contouring and Comparing', written by Baumgart.
The more elaborate example of video assisted drawing is  demonstrated by
the water pump below; the shape of the base and the holes in the
base were derived from a video image.

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