ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001 
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3. Experimental Results 
In order to verify the effectiveness of our proposed methods, we 
have performed a lot of experiments with real world contour lines 
For TIN generation we have used the one provided by 
Shewchuk[4], To evaluate the result visually, we choose to 
generate contour lines of finer interval and compare the result 
with the original contour lines. 
Fig.5 shows partial contour result that is generated with TIN 
generated from real world contour lines that are also used as 
break-line constrains. Thicker lines are the original contour lines. 
The newly generated contour lines have smaller interval than the 
original ones. The result clearly shows that flat regions are 
formed at the locations where original contour lines turn sharply 
and the neighboring contour lies are not close enough. 
Fig.6 shows another processing result for the same original data. 
In this case, the methods stated in section 2 are applied. The 
unnatural contour lines in Fig.5 become more natural ones that 
match their original neighboring contour lines. 
Fig. 5 An example of contour line interpolated from contour lines of wider interval, using original TIN (with contour line as constrains) 
Original flat triangle 
Fig. 4 An example of reconstructed TIN