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Rendering LiDAR with MeshLab
Rendering point clouds originated from airborne laser scanning using MeshLab (cross platform) is a simple process. For using GRASS GIS see also http://grasswiki.osgeo.org/wiki/LIDAR.
Raw Data
The point cloud should be provided as ASCII XYZ data, a three column whitespace separated format. If the available dataset was provided in a different formatting, use an advanced editor like Kate (Linux) or Notepad++ (Windows) to reformat it.
Import
Use File → Import Mesh (Ctrl + H) to import an *.xyz
point cloud.
Normalize
Compute the vertice's normals using Filters → Point Set → Compute normals for point sets. For Numbers of neigbors select a value around 10 to keep the structure crisp enough. Make sure to disable the Flip normals w.r.t. viewport option, as the normals should align only in respect to each other.
Use Render → Show Vertex Normals to check the result.
Surface Reconstruction
To create the mesh use Filters → Remeshing, … → Surface Reconstruction: Ball Pivoting. Do not use the Poisson algorithm as the result require heavy mesh cleaning post processing.
Export
Export the mesh using the PLY format, File → Export Mesh (Ctrl + E) as it can be import with various other 3D rendering application.
— Bernhard 2013/11/29 15:20