TerraExplorer offers an array of tools, which make it easy to analyze and visualize your 3D World, to enhance your geospatial understanding of an area. For a quick overview of analysis tools in TerraExplorer, see our Quick Guide.
In this article:
Analysis Tools Tutorial - Learn how to use the swipe comparison tool, take area measurements, and perform volume analysis
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This tutorial introduces you to some of TerraExplorer's analysis tools, using the Hurricane Michael Damage Management dataset.
- Let's continue in the Hurricane Michael project from the previous tutorial (Open TerraExplorer > Open Project from SGS > Search for mexico_beach_emergency_response and click Open).
- Now let's return to the scene of Hurricane Michael (Mexico Beach) that we visited in the previous tutorial: Expand the Objects and Layers group (folder) and then expand the Locations group (folder) under that, and double-click
to fly to it.
- When dealing with longer term disaster response, it's extremely helpful to be able to compare data from different points after the disaster, to easily visualize what progress has been made. In the Project Tree, expand
. Note that this entry in the Project Tree has a radio button rather than a checkbox . All items in the group are then mutually exclusive, i.e., only one item can be selected at any time. Any Project Tree group can be set as a radio group. Select each of the radio buttons in turn, to compare the disaster site over the initial weeks of recovery. TerraExplorer's Swipe Layers tool helps you detect the changes between two (mesh, point cloud, or imagery) layers in the same location or between one of these layer types and the base terrain. To use the swipe comparison tool below with these layers, we need to change 3D City Models back to a regular group: Right-click the parent group, and then from the shortcut menu, select Properties > In the property sheet Group tab, set Radio Group to No. Then in the Project Tree, select the checkboxes of all the models.

- Open the Swipe tool: On the Analysis tab > Swipe > Swipe Layers > Select two different Mexico Beach layers to compare. Using the tool, you can horizontally swipe between the layers, dynamically revealing and hiding parts of each layer.

- Many roofs were blown in by the hurricane. Some need to be fully replaced but others can be patched. In the Project Tree, expand the Analysis folder, and double-click
to fly to the location of one roof that requires patching.
- Let's measure how much roofing material is needed: On the Analysis tab > Area. Click
to snap the measurement lines to the edges. Then click in the 3D Window to mark the area that you want measured. Right-click to finish. The measured area is displayed in the 3D Window.

- More advanced analysis tools: You can also use TerraExplorer measurement tools to measure volume of debris for disposal. This is done by creating a modify terrain object that flattens your debris pile, and then using the Volume tool to analyze how much debris was in the Modify Terrain object. The Modify Terrain tool modifies the elevation values in an area of the terrain based on the polygon you draw in the 3D Window and the properties set in its property sheet. The surface of the terrain is raised or lowered according to the elevation values of the polygon's points. Let's start by navigating to any pile of debris,
To create a modify terrain object: On the Objects tab > click Modify Terrain. Then in the 3D Window, draw your polygon by clicking to add each of the points of the polygon. Right-click to finish. In the property sheet, set Flat to Yes and Elevation Behavior to Replace. (More about: Creating modify terrain objects)

- Now we'll calculate the amount of debris in this modify terrain object: On the Analysis tab > click Volume. In the Compare field, select Modify Terrain - Select Existing. Then select your modify terrain object from the list, and click Start Calculation. When the analysis is complete, the results are displayed.

- See the resources below for more information on using analysis tools.
Next tutorial >
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Measurement & Analysis |
Terrain Analysis |
Imagery/Snapshot Comparison |
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Elevation/Mesh Comparison |
Shadow Analysis |
Viewshed Analysis |