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Editing – Options and Settings General Settings Snapping – General Settings Snapping to Topology Nodes Stream Digitizing Trace Multi-part Features (Explode!)

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Presentation on theme: "Editing – Options and Settings General Settings Snapping – General Settings Snapping to Topology Nodes Stream Digitizing Trace Multi-part Features (Explode!)"— Presentation transcript:

1 Editing – Options and Settings General Settings Snapping – General Settings Snapping to Topology Nodes Stream Digitizing Trace Multi-part Features (Explode!)

2 Suggested General Editing Settings Set Sticky Move tolerance 50 …………….. Uncheck Stretch Proportionally …………. Uncheck Feature Construction Toolbar.. Stream Tolerance 50 (meters or equiv)… Group 10 ………………………………………….. Click Topology tab Uncheck Stretch topology ……………….. Editor Toolbar: Editor dropdown >> Options

3 USDA-NRCS Digital Soil Survey3 Snapping Settings By default, as you draw soil lines the cursor will ‘snap’ to all visible features. There are many options available to control the snapping environment. Access the Snapping Toolbar via the Editor dropdown menu on the Edit Toolbar

4 USDA-NRCS Digital Soil Survey 4 Determines screen distance for snapping Snapping Dropdown >> Options Snap tips are popups that indicate (optionally) what layer, snap Type, e.g. Vertex, that you’ve snapped to. Tip: “Background” provides an opaque text box behind the snap tip which is useful for viewing over dark colors, e.g. imagery

5 USDA-NRCS Digital Soil Survey 5 Snapping Settings This mini toolbar is handy if you are changing your snapping preferences frequently. This will typically occur when edge-matching or during other data integration tasks. Limit snapping to specific features by toggling the icons on/off (shown with ‘Point’ only selected) Snapping Dropdown has additional options: Points Ends Vertex Edge Start/Stop Snapping Allows Island Polygon using Cut Polygon Tool With Point Features selected, allows snapping to soil polygon NODEs only A topology node; the point where two polygons join

6 USDA-NRCS Digital Soil Survey6 Edge matching Example: Settings limit what Types of feature I can snap to, the snap tips verify that I am snapping to a Node, not a line or vertex.

7 USDA-NRCS Digital Soil Survey 7 Vertex Snapping Example: Snap to Edge will snap anywhere along a given line. Turn Edge Snapping off, verify Vertex Snapping is turned on. This will help avoid accidentally snapping to the line instead of the intended vertices as shown in the graphic below

8 USDA-NRCS Digital Soil Survey8 Helpful Tips: Space Bar – Hold down the spacebar key to suspend snapping without turning it off – This allows you to digitize within the snapping tolerance Revert back to 9.x snapping environment if you prefer – Editor Toolbar >> Editor Dropdown >> Options

9 Exercise – Edge Matching Close ArcMap and/or ArcCatalog if open Navigate to Module 7 >> double-click on Module 7 Edge Match.mxd to open the map Begin Editing Set Snapping Environment (Editor dropdown >> Snapping Toolbar) Point Snapping checked Toggle all other snapping features OFF (e.g. end, vertex, edge) Check the following from the Snapping dropdown >> Snapping turned on Snap to sketch checked Snap to Topology Nodes

10 We want to create an Exact Join (node-to-node) in the spatial data Click Bookmarks >> Edge Match Click the Build Topology Cache button on the Topology Toolbar Select the large NOTCOM polygon in NE160 Select the Cut Polygon tool Snap to a topology node to begin and end the new polygon

11 Double-click on the topology node to finish Attribute the new NE160 polygon with the same MUSYM as the joining NE159 polygon Add several more polygons using the same procedure Note: if unable to snap to Topology Nodes, be sure to click Build Topology Cache again Save Edits, Leave ArcMap open

12 USDA-NRCS Digital Soil Survey 12 Stream Digitizing Stream digitizing allows the user to draw using the mouse in a smooth fluid motion. Vertices are added automatically at a user-defined interval BewareBeware, when stream digitizing Easy to create high vertex density, i.e. multiple redundant vertices Easy to create topology errors until proficient Requires patience and practice

13 USDA-NRCS Digital Soil Survey13 Stream Digitizing - Settings Editor>Options>General Stream tolerance is the interval at which vertices will be added, here 50 meters (do not set less than 30 meters) Group is the number of points grouped together that will be deleted using the Undo button (or Ctrl Z)

14 USDA-NRCS Digital Soil Survey14 Stream Digitizing Tips: The F8 key toggles between manual and stream mode The ‘C’ key is a shortcut for the PAN tool. While stream digitizing, be ready to hold down the ‘C’ key with your free hand. This will stop the current action, allow you to Undo or select another tool. If using Stream digitizing to cut an island be sure the Snap to Sketch option is turned on.

15 USDA-NRCS Digital Soil Survey 15 Snap to and double-click on starting node to complete

16 USDA-NRCS Digital Soil Survey16 Be careful. It is very easy to “double-back” on your line when stream digitizing. This will create sliver polygons or worse…

17 Exercise – Stream Digitizing Open Module 7 Edge Match.mxd and Begin Editing if necessary Editor Dropdown >> Options Set Stream Tolerance to 50 map units Group 10 points together Turn on End Snapping and verify that Snap to Sketch is checked Verify that the Function keys are active on your keyboard (i.e. the ‘F’ keys; F8)

18 Bookmarks >> Stream Digitize Select the large NOTCOM polygon, then Cut Polygon tool Click once to begin cutting an island polygon Click F8 key, click again and notice you are in streaming mode Left-click to pause Streaming Click Ctrl+Z >> the last ten vertices are removed You may remove another 10 by clicking Ctrl+Z again Left-Click to resume Stream Mode Click F8 again to exit stream mode Make several polygons this way – Try Edge-Matching or Reshaping an Edge using Streaming mode Save Edits, Stop Editing, Close ArcMap TIP: TIP: It is often difficult to double-click on the starting point in order to finish the cut polygon edit while using stream mode. Instead, left-click to Pause streaming, then snap to starting node and double-click to finish edit. Stream Digitizing Ctrl+Z Deletes Last 10 Vertices

19 Trace Tool The trace tool allows you to trace along an existing line from any vector layer in the map during standard editing procedures, e.g. Cut Polygon, Reshape Edge, Create New Features. Tool could be used in cases where you want a soil polygon to exactly match a line from another layer, e.g. a contour, an ownership or management boundary, or existing soil data. Example: Black boundary is the project area. It includes areas that were mapped previously (orange). Create new polygons in project area using Cut Polygon by Tracing orange lines that you want to keep. Zoom in to area of Red circle (next slide)…

20 Select large NOTCOM polygon >> Cut Polygon Tool Then Select Trace Tool from the Editor toolbar. Click on orange line outside the selected polygon and move mouse along line. The orange line is traced exactly Left-click to Pause tracing Click the Line Segment tool from the Editor Toolbar to continue drawing normally Start Cut on orange line Outside of Selected Polygon Left-Click to Pause Trace >> Select Line Segment Tool from Editor Toolbar L-click

21 Click Line Segment Tool Finish Edit Sketch by inserting vertices with Left-click Double-click to finish Result (traced layer in light gray)

22 Exercise - Trace Open Module 7 Trace.mxd Set the ne160_a symbol to hollow, green outline, thickness 2 Now you can now see ne159_a data underneath From the menu along the top Bookmarks >> Trace Start Editing >> Select the ne160_a geodatabase Set Selectable Layers to ne160_a only (make ne159 unselectable) Select the big NOTCOM polygon in ne160_a Select Cut Polygon tool Then click the Trace tool Start outside the ne160_a polygon and click on the ne159_a line to begin tracing… Left-click to pause tracing when you reach the straight north-south line

23 Exercise – Trace Continued With Tracing paused, select the Straight Segment tool from the Edit toolbar to return to manual construction, i.e. left-click to insert vertices When the cursor enters the data frame, you will be connected to the last point before you paused tracing Finish the edit by left-clicking to add vertices as shown, snapping to the ne159_a vertex just across the selected line, dbl-click to Finish Attribute the new polygon Cut several more polygons using Trace >> L-click Pause >> Straight Segment >> Snapping >> Attribute Save Edits, Leave ArcMap open

24 Multipart Features What? A multipart feature is a single feature that contains more than one polygon, line, or point. If you select a multipart feature in the map, more than one polygon is selected. However, those multiple polygons represent ONE feature and thus the attribute table will only have one record (row) selected. Why? For example, in a feature class of the 50 United States, you want 50 records in the table. If you select Hawaii in the table, only one record will be selected, i.e. one feature (state) But multiple polygons selected in the map, the group of islands that constitute HI. Alternatively, if you select any ONE Hawaiian Island in the map, ALL polygons will be selected and only one record in the table, the state of Hawaii.

25 How to Create? Multipart features may be created by simply using the Merge function on the Edit toolbar. Polygons don’t have to be adjacent to be merged. Multipart features also result from geoprocessing operations, commonly the Dissolve tool. They can be created accidentally under certain circumstances. How to Separate into Discrete Features? Use the Explode Multipart Feature tool (found in Advanced Editing Tools) to create a separate feature for each polygon, line, or point. When are they used in soils? Multipart features are typically NOT used and should be avoided when developing (editing) soils data Multipart features are sometimes helpful for analysis, e.g. to reduce the total number of records in a table, etc. TIP: Because multipart features are treated as a single feature, the AREA is the sum total of all of the polygons. For this reason, before calculating Acres, it is a good idea to Select ALL >> Explode multipart features. This ensures that there are no sliver polygons that included in a multipart feature.

26 Exercise – Multipart Features Open the Module 7 Trace.mxd if necessary Stop Editing if necessary Turn off the ne160_a from the previous exercise Set Selectable Layers to ne159_a only From the top menu Selection >> Select by Attributes Type the following selection equation: MUSYM = ‘2Bu’

27 Exercise – Multipart Features Continued Begin Editing >> Select the ne159_a geodatabase Editor dropdown >> Merge Select any polygon to merge (all polygons have the same AREASYMBOL and MUSYM) Open ne159_a Attribute table >> view Selected Note that there is a single feature selected in the table. Multiple polygons are remain selected in the map. The Shape_Length and Shape_Area attributes are the sum total perimeter and area (sq. m) respectively If you edit the attribute table, e.g. change the MUSYM, it applies to ALL the polygons

28 Exercise – Multipart Features Clear select features Navigate to Bookmarks >> Multipart Feature Turn on Labels (set to labels to MUSYM in properties if necessary) Select the 2Bu polygon in the center of the screen using the Select Features Tool From the top menu, Selection >> Zoom to Selected Features Note that it zooms out to ALL of the polygons … they are multiple parts of one feature Next, Click Explode Multipart Features tool Note that this clears the selection Selection >> Select by Attributes (the previous query should still be there, otherwise reenter MUSYM = ‘2Bu’) Open the ne159_a attribute table Note that there are now 7 polygons selected, each with its own attributes

29 DEMO Inadvertently Creating Multipart Features Working with a Dissolved Soil Layer


31 31 Avoid Redundant and Excessive Vertices? Why? Increases file size Decreased performance for – Applications (like Web Soil Survey) – Geoprocessing – Editing – File transfer (like check-in/check-out)

32 32 How many is too many? More than needed to represent a feature within SSURGO standards at publication scale. Too many! Just right!

33 33 How to prevent excess vertices? If Stream Digitizing, use the recommended 50m Stream Tolerance Do not zoom in too far and digitize unnecessary detail Rule of thumb is to digitize around 1:6000 scale (1:4K – 1:8K) Rarely zoom in beyond 1:3000 Lines should maintain quality, e.g. smoothness, feature representation, etc., at 1:6000 scale

34 How to prevent excess vertices? Do NOT Use: Arc Segment Tangent Curve Segment Bezier Curve Segment Do NOT Use: Circle Ellipse Freehand Do NOT use the any Edit tools or Construction tools that utilize Arcs

35 Why Not? These curve geometries are calculated curves between two vertices Note that this polygon contains only four vertices Between the vertices are Arcs Editing a single vertex results complex curves Shapefiles and other formats do not support Arc geometry These arcs are converted to 100s or 1000s of vertices in other formats

36 Summary Use the Snapping options to assist in Quality Control Stream digitizing can produce nice smooth lines, but use with care: – Practice to avoid self-intersections when drawing – Use a Stream Tolerance of 50m The Trace tool may be useful in some circumstances so remember it is an option Avoid Multipart Features – periodically select all features and Explode! Avoid Excess Vertices – Don’t zoom in beyond what is reasonable – Zoom back out to “publication scale” to verify line quality – Avoid ALL tools that use Arc geometry between vertices, manually create arcs using straight segments

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