Starting data
The starting data is the file 'topo_nlc.dat', that is a text file with xyz of a grid (5800 points)
| Code Block |
|---|
-9400 -2884100 1557.5228971414 -9201.7543859649 -2884100 1558.9433292625 ... 1900 -2864400 1564.971922013 |
Files->Import->XZY points...
It is a flat topography, for tutorial purposes will scale z by 50 with Utilities->Move... tool
...
A common graphical problems is that topographic models are mapped from the curved earth to a planar representation with UTM projection and this could become in too big x,y 2D coordinates (model box far from the origin). This is a graphic problem drawing with OpenGL that uses float real numbers for coordinates (about 7-8 significant digits). Staircase graphical artifacts, and the selection in screen could become a little displaced of the entity drawn. An easy solution is to translate the model in XY near the origin.
How to create a surface model?
The model has only points, not surfaces. There are different ways to create surfaces
- Connect with '2D Delaunay triangulation'
It could be done selecting a checkbox when importing or after with process commands (Mescape Meshing ConnectPoints CreateSurfaces)
- Create a single smooth NURBS surface approximating the cloud of points
Geometry->Create->NURBS surface->By points
