CAD Upgrade – Join, Break, and Explode
Discover three useful CAD tools introduced in 3Dsurvey version 4.2: Join, Break, and Explode. These features make it easier to edit polylines, repair polygons, and work more efficiently with CAD geometry. In this tutorial, we’ll explore how each tool works and how you can use it in real-world surveying projects.
Join Tool: Combine Lines into a Polyline
The Join Tool allows you to combine separate line segments into a single polyline with just a few clicks.
How to Join Lines
Select the line segments you want to connect and activate the Join Tool. The selected segments are combined into a single polyline, retaining their existing vertices.
You can also select multiple groups of connected lines at once. Each group will become its own polyline, allowing you to join several features in one operation.
Join Existing Vertices
The Join Tool connects existing vertices without creating new ones. When the selected segments form a complete boundary, the tool can also close the polyline automatically.
This is particularly useful when working with lines that have been drawn separately but need to form a continuous or closed shape.
Join Tool in Practice: Volume Calculations
One of the most useful applications of the Join Tool is preparing boundaries for volume calculations.
When calculating volumes, you may need to define an area using a closed CAD polyline. However, when switching between different views or mesh tabs to inspect the area, your drawing process may be interrupted, leaving you with multiple separate lines.
If the resulting polygon is not closed, 3Dsurvey cannot use it to define the calculation area.
How to Fix an Open Polygon
Draw the boundary using separate line segments as needed.
Select the relevant lines and activate the Join Tool.
Allow the tool to combine the segments into a single polyline and close the boundary where possible.
Open the volume calculation tool, select the required surfaces, and choose the CAD-based area selection.
Your joined, closed polyline can now be used to define the calculation area without having to redraw the entire boundary from scratch.
Explode Tool: Split a Polyline into Individual Lines
The Explode Tool performs the opposite operation to Join. It breaks a polyline into its individual line segments, allowing you to edit specific parts of a shape independently.
How to Explode a Polyline
Select the polyline you want to edit and activate the Explode Tool. The polyline is split into separate lines that can be modified, moved, or deleted individually.
This is especially helpful when working with imported CAD or cadastral data that contains incorrect or unwanted geometry.
Repairing an Incorrect Polygon
Imagine importing cadastral data and discovering that one of the polygons contains an incorrectly shaped corner.
Instead of redrawing the entire polygon, you can:
Turn off or lock unnecessary layers to make editing easier.
Select the affected polygon and use the Explode Tool to separate it into individual lines.
Keep the segments that are still correct.
Use the Intersection Tool to establish the correct corner between the remaining segments.
Delete the unwanted lines and geometry.
Select the corrected segments and use the Join Tool to rebuild the polygon as a single closed polyline.
This workflow lets you repair the affected area while preserving the geometry that is already correct.
Two Ways to Use the Join Tool
You can join line segments by selecting them all before activating Join. Alternatively, activate the Join Tool and click the resulting geometry to combine the segments. Both methods can achieve the same result, depending on the workflow you prefer.
Break Tool: Remove a Section of a Line
The Break Tool allows you to remove a selected section of a line or polyline, creating a gap between the remaining parts.
How to Break a Line
Activate the Break Tool.
Click the point where the break should begin.
Move along the line to the desired endpoint.
Click again to complete the break.
The section between the two selected points is removed, leaving an opening that you can modify or fill with new geometry.
Example: Adding a Road Junction
Suppose you are vectorizing a road and need to add a new junction. The existing road boundary must be interrupted to make room for the new connecting lines.
Using the Break Tool, select the starting and ending points of the section you want to remove. Once the gap is created, draw the new lines needed to form the junction.
Repeat the process on the other side of the road if necessary, then add the remaining geometry to complete the junction.
This approach makes it easy to modify existing road layouts without redrawing the entire line.
Summary: Which CAD Tool Should You Use?
The Join, Break, and Explode tools give you more flexibility when creating and editing CAD geometry in 3Dsurvey.
Join: Combines connected line segments into a polyline and closes the boundary when possible.
Explode: Splits a polyline into individual line segments for detailed editing.
Break: Removes a selected section of a line to create a gap for further modifications.
Whether you’re preparing boundaries for volume calculations, repairing imported cadastral polygons, or updating road layouts, these tools help simplify your workflow and reduce the need to redraw existing geometry.
Explore these features in your next project, and check out the other 3Dsurvey tutorials to discover more CAD improvements.
