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Creating and Modifying Features. Lecture 16. How Feature Data is Stored. Endpoints Initial and final point when creating a line Vertices Point where a line segment changes direction Edges The line segment between endpoints and vertices. Edges (Line Segment). Vertices. Endpoint.
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Creating and Modifying Features Lecture 16
How Feature Data is Stored • Endpoints • Initial and final point when creating a line • Vertices • Point where a line segment changes direction • Edges • The line segment between endpoints and vertices
Edges (Line Segment) Vertices Endpoint • Polygon • The feature formed when a line segment ends at the original endpoint.
Lines will follow vertices if: • Vertices are moved • Vertices are added
Digitizing • The process of creating a digital feature. • Digitizing Table • Placing a map or photo on a table that is connected to a computer. • The features to be digitized are traced with a puck (similar to a mouse) to input the data.
Heads-up Digitizing • Features are drawn with a mouse directly on the computer screen by tracing the features on an aerial photo, a scanned map, or other spatial data. • Created within ArcMap • ArcGIS has several tools for creating circles, rectangles, curves and other shapes. • Digitizing can create features in a new or existing shapefile.
Creating a New Feature • In ArcCatalog • Create a new shapefile for the new feature. • ArcCatalog • File • New • Shapefile (Buildings)
In ArcMap • Create the new feature • ArcMap • Editor Toolbar Button • Editor pull down menu • Start Editing • Task • Create new feature • Target • New Shapefile (Buildings) • Editor pull down menu • Snapping • Vertex (Lines will snap to existing features in the layers selected).
Sketch Tool • Click on first point (endpoint) • Click on second point • Etc • Double click on last point to establish polygon. • Editor pull down menu • Save edits • Saves the polygon in the shapefile. • Editor pull down menu • Stop Editing
Modify Features • Editor Toolbar Button • Editor Pull Down Menu • Start Editing • Edit Tool • Task • Modify Feature • Double click on line • Click and drag vertices to reshape • Right click on an edge to open the context menu which has several options, including “Insert Vertex” • Click on a Feature to select it • Delete button on the standard toolbar will delete the selected feature. • Editor Pull Down Menu • Save Edits • Stop Editing