How to do CMS modelling
The following steps show how to import and cleanup Cavity Monitoring System (CMS) data into Surpac. Using some of the Surpac tools it is possible to significantly reduce the number of points in the CMS file without altering the volume or essential shape.
1. From the File menu, select Import, then Cavity monitoring DXF file.
2. Open the CMS data file
3. From the Solids tools menu, select Create sections.
4. Define a vertical axis. Slices will be created, perpendicular to this axis.
5. Use the layer chooser to set the layer named section as the current layer.
6. Turn Faces Off, and spin the data around.
7. Use the cleaning tools in Surpac to minimise the number of points before re-triangulating the closed segments.
8. From the Edit menu, select Layer, then Clean. Often, due to data geometry, the removal of duplicate points with the CLEAN LAYER function must be run multiple times to ensure all data points are deleted.
9. Repeat the previous step until you see only the following two lines in the message window:
Searching for duplicate points
100 percent complete
10. Save the file. From the File menu, select Save, then String/DTM file.
11. Next, remove all closed segments less than a specified area.
12. Another common way to clean up the data is to delete segments with only a small number of points.
13. Last, we will check for spikes. From the Edit menu, select Layer, then Clean.
A red marker will be placed on any spikes detected, you may need to use the Edit tools to either delete or move points.
14. Next, triangulate the data to create a closed solid. One method of doing this is to use Triangulate – Many segments. We will first want to look at the segment numbers.
15. From the Display menu, select Strings, then With string and segment numbers. Leave the form as displayed and click Apply.
16. From the Solids > Triangulate menu, select Many segments.
17. From the Display menu, select Hide DTM, and Apply the form. We will be triangulating a range of segments. Alternatively, you could manually triangulate each slice.
18. Validate and turn the object into a solid.
19. Generate a volume report.