Algorithms for Triangulated Terrains
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Citations
Geographical Information Systems: Principles and Applications
GPSLoc: Framework for Predicting Global Positioning System Quality of Service
The development of a teaching tool using Sketchup to enhance surveying competence at the Durban University of Technology
Improving the accuracy of digital terrain models
Geometric Spanners in the MapReduce Model
References
Computational geometry. an introduction
Computational Geometry: Algorithms and Applications
On the Theory of Scales of Measurement
Spatial Tessellations: Concepts and Applications of Voronoi Diagrams
Computational Geometry: An Introduction
Related Papers (5)
Adaptive Tessellation Method for Creating TINs from GIS Data
Frequently Asked Questions (10)
Q2. How can the authors redistribute the points over the k triangles?
But redistribution of the points can also be done in O(k+m logm) time by sorting the m points by angle around p. Since all new triangles in the TIN are incident to p, the authors can distribute the m points over the k triangles by using the sorted order.
Q3. How many neighbors do the authors want in the chosen independent set?
we'd like all vertices in the chosen independent set to have constant degree in the graph, say, each chosen vertex has at most ten neighbors.
Q4. What are the types of man-made geographic data?
Borders of countries and provences, locations of roads and hospitals, and pollution of the lakes and rivers are types of man-made geographic data.
Q5. How does depth-rst search for a TIN map work?
Both the triangle-based and the edge-based TIN structures implicitly store this graph, and depth- rst search through all the triangles is easy if a mark bit is available in every object, to see if it has been visited before.
Q6. How can the authors produce a TIN from a view?
The authors can produce such a view using the Painter's Algorithm, where all triangles are drawn from back to front, so that the ones more to the front erase the ones more to the back.
Q7. What is the algorithm that we'll describe?
The algorithm we'll describe selects a subset of the grid points, such that the Delaunay triangulation of this subset is a TIN that approximates the elevation at all grid points to within a prespeci ed error .
Q8. What is the relation between the number of edges and triangles?
By Euler's relation for planar graphs, the number of edges and triangles is linear in the number of points, the vertices that determine the subdivision.
Q9. What is the common method of converting a TIN from digital elevation data?
This can be the triangulation between contour lines, grid to TIN conversion as in this paper, or producing a TIN from point data, with or without an interpolation method.
Q10. How can one compute contour lines of a given elevation in depth- rst?
So for a TIN with n vertices and, hence, O(n) edges and triangles, one can compute all contour lines of a given elevation in O(n) time by depth- rst search.