Design Block Boundaries tool creates shape elements that can be used as block boundaries for a TerraScan project. The block boundary creation can start from line or shape elements. If points are loaded in TerraScan, the tool can also compute the amount of points inside each block boundary.
The line elements used as starting elements for the tool should cross each other in order to create a closed line work for the shape creation. If shape elements are used as starting elements, the tool does not create new shapes. It only computes the amount of points inside the existing shapes.
The amount of points inside each block area is shown by text elements, which are drawn into the design file. The color of the label indicates whether the amount of points inside a block is within a given range. The point count is given in values rounded to million points. If no points are loaded in TerraScan, the tool ignores settings related to labels and point counts.
The tool supports significantly the creation of block boundaries for TerraScan projects, especially if the point density is varying in the project area. This is often the case in mobile mapping projects if the driving speed is not constant.
To design block boundaries:
1. (Optional) Load points from the whole project area into TerraScan using Read points command or Load Airborne Points tool. Load only a subset of points if the project area is too big to load all points.
2. Use MicroStation or TerraScan tools to digitize line elements around your project area and to separate the project area into smaller parts.
3. Select the Design Block Boundaries tool. This opens the Design Block Boundaries dialog:
4. Define settings and click OK. This creates shapes on the given Shape level. If points are loaded in TerraScan, the tool creates text elements on the given Label level.
5. If the amount of points per block is not within the given limits, modify the line work. Run the Design Block Boundaries tool again in order to update the shapes and labels. Continue until the point counts are within the limits.
6. Continue with the Define Project tool in order to add the shapes as block boundaries to a project.