In this document we’ll cover the different geometry tools available to support data collection in the Coreo app, and look at how to use them.
The tools you will see in your project depend on the geometry types your form is setup to use. For example, your project might be configured to only allow the recording of point location data. In this case, you will not see any of the tools which support the editing of polygons, such as the cut, split and merge tools.
Adding a location feature
If your project supports more than one type of geometry, first select the one you need, using the dropdown in the upper left corner of the screen. If you only have one type available in your project, this will be automatically selected.
The point feature is very straightforward to use. Simply move your cursor to the desired location and tap the blue button in the bottom right to drop your data point. Its position can be adjusted using the drag handle.
The polygon feature allows you to draw an area on the map. There are two ways you can draw your polygon:
- By dropping points
- By freehand drawing a line using the Draw tool
Method 1 – Dropping Points
- Once you have selected Polygon using the upper left dropdown, find the location where you wish to draw your polygon on the map.
- Move your cursor over an edge or corner of your location and then tap the blue button to drop your first point.
- Move your cursor to the next area on the location and press the blue button and drop another point. A line connects the two points.
- Repeat this until the polygon is your desired shape.
Now that your polygon is complete you can manipulate it further, in order to refine its shape.
- You can tap any of the points to select them. You can then drag them to your desired location, either by holding the point itself or the black drag handle attached to it.
- You can add new points to your polygon. To do this, move your cursor to an edge and you will see the cursor snap to it.
- Tap the blue button to drop another point onto the line.
Method 2 – The Draw Tool
To use the Draw tool, you must again either be working with a polygon or line.
- Select the white pencil icon above the Add point tool
- Once selected the Draw icon will highlight and the Add point tool will become unavailable.
- Draw out the shape of your polygon, either using your finger, a stylus or your mouse.
- Once complete you will see the polygon has vertices. As with the previous example, you can select and manipulate these individually, as required.
This feature allows you to place multiple polygons associated with a single record. The tools are identical to those outlined above, however on completion of your first polygon you will be prompted to draw another. You can select it from the white dropdown menu in the top left
Additional Polygon Tools
There are three additional ways for you edit your polygons. They are the three icons to the top right of the screen.
First the cut out tool
- This tool allows you to cut out a section from your polygon. This is useful for excluding certain geographical features from your parcel such as lakes.
- Select the cut out tool, you will then have the option of using the node tool or draw tool to draw the shape you want to cut out
- You can remove sections from both the middle of your polygon and the edges
- When using the draw tool an area will be cut out as soon as you have finished drawing your shape
- When using the point dropper tool, create your shape as normal
- When you are happy with the area you wish to cut, tap the blue ‘Complete Cut Out’ button
The split tool allows you to split an existing polygon into two separate polygons.
- Select the split tool in the top right
- You can then draw a line across your polygon by dropping two nodes or by using the draw tool
- Once you’re happy with your line tap complete split, your polygons will now be separate
- These polygons can both be manipulated as normal
Finally the merge tool allows you to add a polygon to an existing polygon.
- Select the merge tool
- Once again you will have access to your node tool and draw tool
- Draw your new polygon ensuring there is some overlap with the existing polygon you wish to add it to.
- When happy with your addition tap complete merge and your polygon will be expanded
The line string tool allows you to draw a line on your map. Once selected you can use either the node tool or the draw tool to draw your line
For more context on how these may be used in a project see our How to guides for UKHab.