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GeoWin DTM |
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Triangle mesh (TIN) |
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Contours |
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Longitudinal profiles - cross section |
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Curve tools |
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Survey points |
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Computation |
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Other |
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Advices for work with
GeoWin-DTM
GeoWin
DTM is designed for AutoCAD, BricsCAD and GstarCAD.
1. Creating TIN - Triangulated Irregular Network
The
sketch should be prepared for the correct creation of triangulated
network.
That means: removal of all points, which negatively affect the
elevation course, adjustatment of breaklines so they would not
cross or overlap each other. The program tries to notice and fix
all these encounters, however, it is forced to remove few edges
from the process sometimes.
If the sketch contains islets (holes), it's advised to draw their
circumferences with 3D curve in individual layer. As an input set
of points, the following is usable: coordinates from file, or
coordinates of objects (POINT type or BLOCK type). Accuracy of
these coordinates is reduced to three decimal places, for better
manipulation with breaklines, which also participate in
triangulation with their coords. It is possible to use
triangulation only with breaklines, without a set of points.
2. Creation of contours.
Algorithm
for smoothing out TIN is sensitive to arrangement of input set of
points.
TIN should have its triangles, as similar as possible
to equilateral ones,
which is sadly very unlikely. Introduction of breaklines makes the
situation even worse, because of frequent creation of obtuse
triangles, which contribute to serratedness during the creation of
contours. It's also advised to be careful, and not to forget set
sharp breakline, because forgetting it might cause the overcrossing
of contour.
3. Computing difficulty
Theoretically
it's possible to compute unlimited number of points, however the
application is limited by the amount of available RAM. Increasing
level of smoothness and number of points increases memory
requirements.
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