select 
select 
ecting 
ke the 
ar the 
inputs 
ig the 
most 
vable 
Xd. In 
'ertex, 
n has 
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it can 
when 
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S the 
imply 
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ost fit 
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d it is 
:grity. 
of the 
The 
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d the 
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;antly 
dels, 
ırther 
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jects 
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ation 
d of 
on or 
om a 
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bject 
The 
view 
ating 
The 
er to 
on of 
es of 
gh to 
le in 
ints. 
ipler, 
time 
n of 
ace. 
Je to 
face 
is not visible, a texture or color for the face can be 
chosen elsewhere. 
CONCLUSION 
We have presented an interactive technique for 
extracting 3-D models from single or multiple 
photographs. This system does not require 
precomputed camera models, terrain elevation data 
or ground control points. An algorithm was 
discussed which fuses all input data into an overall 
best fit for the model. PolyFit outputs polygonal 
mesh polyhedral models and, if not provided, 
camera models. PolyFit also extracts photo-texture 
for each face of the polygonal mesh for realistic 
rendering from new vantage points. The model 
construction process has been streamlined by a 
sound graphical user interface. 
PolyFit's success comes from its ability to combine 
the human's photointerpretation skills with the 
computer's computational capabilities. Success has 
been demonstrated through extensive use by 
modelling engineers of GE's Simulation and Control 
Systems Department. 
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