• For large scanning files
• Reads LAS format, ASCII format
• Creates TPC files in Topocad
• Creates terrain models from parts of a point cloud
• Creates contour lines from scanning
• Function to avoid noise in point clouds

Topocad Point cloud is a new module which reads the scanning format LAS – the standard for scanning. The module uses the LAS files from scanning instruments as well as other file formats such as PTS, XYZ and other ASCII files.

Topocad has its own internal format, TPC (Topocad Point Cloud), an indexed file with functions for import of other scanning file formats as LAS files. The TPC file will be possible to use instead of, or in combination with, DTM files. In Topocad it is possible to use this format instead of terrain models when you create a terrain section or contour lines.

You cannot create a DTM from a point cloud directly, but you can create contours and then create a dtm from those. Once you have imported a point cloud and saved the tpc file, you can open a new drawing document and start the “Volume comparing two DTMs” command (it is located in the menu under DTM). In the models tab you can choose your tpc file as “surveyed” and you can use either a fixed level or another tpc as “theoretical”. Enter the contours tab and check “Create contour lines”. Press OK to generate the contours. Depending on the size of the models you may want to try different intervals in the settings tab.

Topocad can create terrain models and also take parts from the TPC file to create a terrain model. This module can manage very large amounts of data and from this create the ”common” data we usually work with, for example terrain sections and also create terrain models from parts of a point cloud which can be used for volume calculation and sections.

Topocad has a new method to avoid noise in the point clouds, for example trees that can be included incorrectly. The method is called ”Roll a ball” and reduces a number of points, and only the points that actually should be in the terrain model are included. The idea is to roll a fictitious ball beneath a point cloud – and only the points that are touched by the ball remain in the point cloud. You can change the radius of the ball to include more or less points and test different sizes to get a model that fits your work. Blades of grass disappear at the first attempt and by selecting just the right diameter you will also get rid of trees. Some objects, like houses, are harder to remove with this method but they are easier to edit in a terrain model.

It is also possible to create contour lines from point clouds by using the command ”Volume between models” and set the reference level to 0. In the command you can also calculate volumes between two point clouds or between a point cloud and a terrain model, for example an excavation bottom.