Spatial Manager™ for AutoCAD - FAQs: GIS Analysis ("Professional" edition only)

Notes:

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Introduction

• Objective of this section
  • To learn how to use advanced GIS analysis tools in your drawings and maps

• Topics in this section
  • Create Buffers from point, linear or polygonal borders objects
  • Process spatial Overlays which will create new drawing objects based on the operation results
  • Dissolve polyonal objects in order to create surrounds of adjacent objects
  • Create Centroids from selected polygons
  • Calculate and draw Areas of Influence from selected point objects

GIS Analysis tools

Spatial Manager™ for AutoCAD includes a set of advanced tools designed for geometric and spatial analysis of geographic objects and their geometric relationships, resulting in new objects generated from the resolution of such analysis

Note: The GIS Analysis tools were introduced in the version 7 of the application, so are not available for some old Autodesk products

Performing GIS Analysis in the drawing

About objects selection

Some of the analysis tools described below allow object selections before or during their execution. Even some of them (SPMOVERLAY) allow you to select two groups of objects to operate between them. For all of these commands, the following notes and instructions apply:

• Select all objects: All objects in the drawing will be processed
• Only selected objects: Only a selection of objects will be processed. You can select the objects before executing the commands or by using the Selecting buttons in their corredponding windows
  • Manual selection
  • Select by Query: Select objects according to the result of a simplex or compound data query (See "Selecting by Query")
  • Select by Table: Select objects which have been previously attached to a specific data table (See "Selecting by Table")
    • Note: As you can select the objects previously to execute the commands, in addition to the use of the above included selection options or in combination with them, you can make use of some other Advanced selection application tools, select objects in the Data Grid or any other selection method available in AutoCAD (Quick Select, etc.). Also note that, as most of the advanced application or AutoCAD selection commands will let you apply the selection to the current selection, the number of possible combinations to select what you are interested in is almost unlimited
• Select objects in a layer: Only the objects included in an AutoCAD Layer will be processed. You can select the layer using the drop-down list in this window

Note: The selection of objects in AutoCAD may be a few slower when the "SpatialManager" palette is open, depending on the data of the objects

Buffer

The command 'SPMBUFFER' in Spatial Manager™ for AutoCAD allows you to generate Buffered polygons around point objects, linear objects or polygon boundaries. Buffer distance can be constant or taken from the value of a table field for each object, it is possible to merge the generated objects in their common areas and different styles of joins and endings can be chosen

• Objects selection: See the paragraph "About objects selection" above
• Buffer options: You can select the Buffer distance (fixed value or field-based value), the Join and End cap styles, the Buffer Units conversion (so you can define the Buffer distance in units other than the drawing units) and if you want to Dissolve/Merge the generated Buffered polygons
• Table/Layer name: This setting defines the target Layer and data table name for the Buffers. You can select an existing Layer in the drawing or you can write the name to create a new Layer. Buffer objects will adopt the same data as the objects that generate them, unless the "Dissolve/Merge" option has been checked, in which case this would not make sense and the combined Buffer objects are not attached to any data table
  • Apply random colors to new Layers
• Create: Dissolved objects type, Borders or Polygons. The Polygons option allow you to select MPolygons as the type of object to use. This options is available on all compatible Autodesk products (even on vanilla, plain or basic AutoCAD) (AutoCAD 2013 and upper). The MPolygons can be defined by multiple rings, even including holes, as a single AutoCAD object
  • Fill areas using Hatches
• Treat closed polylines as polygons: When checked (default value), all closed Polylines in the drawing will be considered as Polygons and not as linear objects. Most of the time the closed polylines represent polygonal elements

Overlay

The command 'SPMOVERLAY' in 'Spatial Manager™ for AutoCAD' allows you to create new objects based on geometric and data operations between two existing object groups

This function allows you to generate new objects in the drawing by performing "geometric operations" between two groups of existing objects: "Source" (Group 1) and "Overlay" (Group 2). For example, according to the chosen parameters in this image, for all selected Source objects (Roads, etc.) that are located within any Parcel, the Overlay Identity function will create new objects which will are equal to the Source objects "broken" in the Parcels limit

• Objects selection: See the paragraph "About objects selection" above (Group 1 and Group 2)
• Overlay parameters and options
  • • Intersect:
    • Union:
    • Erase:
    • Identity:
    • Clip: A geometry is Disjoint from another one if they do not have any points in common (that is, "out of": It does not intersect and does not touch). It is the opposite of 'Intersects'
    • Paste:
    • Symmetric Difference:

Dissolve

The command 'SPMDISSOLVE' in Spatial Manager™ for AutoCAD allows you to generate new Polygons based on the grouping of other adjacent polygons with some common data

• Dissolve options: You can select the common Table/Field data for dissolving the polygons (even including null data). To reduce possible precision errors in the geometry, you can check the option to generate a temporary small buffer around the polygon boundaries in order to avoid as much as possible the generation of inner holes during the operation. Check the option "Create labels" if you want to Label the common data for every new polygon
  • Label options. You can define the Style, Height and Justification of the Label Text objects here. You can configure if you want to insert the new Polygons geometry and its Labels or the Labels only. Be careful: if you check this box you will only get the Labels (Text objects) but not the dissolved polygons. As added parameters, you can set the option to use or not LUPREC for decimal places (see Notes below) and Mask labels which will generate masks (Wipeout objects, grouped with the Labels) and they will "trim" the objects located behind the Labels in order to improve its reading
    • Notes:
      • You can choose that the value of the LUPREC variable (Length precision) be used or not for the number of decimal places when labeling objects using a numerical field (Please, take a look to LUPREC and UNITS in the AutoCAD Help)
      • Label Masks may have some functional issues or may not be available in versions earlier than AutoCAD 2017
• Table/Layer name: This setting defines the target Layer and data table name for the new dissolved Polygons. You can select an existing Layer in the drawing or you can write the name to create a new Layer. Dissolved polygons will include the common dissolve data (1 field) as the polygons to dissolve
  • Apply random colors to new Layers
• Create: Dissolved objects type, Borders or Polygons. The Polygons option allow you to select MPolygons as the type of object to use. This options is available on all compatible Autodesk products (even on vanilla, plain or basic AutoCAD) (AutoCAD 2013 and upper). The MPolygons can be defined by multiple rings, even including holes, as a single AutoCAD object
  • Fill areas using Hatches
• Treat closed polylines as polygons: When checked (default value), all closed Polylines in the drawing will be considered as Polygons and not as linear objects. Most of the time the closed polylines represent polygonal elements

Centroids

The command 'SPMCENTROID' in Spatial Manager™ for AutoCAD allows you to generate Centroids (Point objects) for the selected polygons. The polygons data (if any) will be attached also to the Centroid objects

• Objects selection: See the paragraph "About objects selection" above
• Table/Layer name: This setting defines the target Layer and data table name for the Centroids. You can select an existing Layer in the drawing or you can write the name to create a new Layer. Centroids objects will adopt the same data as the corresponding polygons
  • Apply random colors to new Layers
• Treat closed polylines as polygons: When checked (default value), all closed Polylines in the drawing will be considered as Polygons and not as linear objects. Most of the time the closed polylines represent polygonal elements

Areas of Influence

The command 'SPMINFLUENCEAREAS' in Spatial Manager™ for AutoCAD allows you to generate Polygons defined by the set of points closest to each point of a selection of Points in the drawing (Voronoi diagram). Each Polygon generated will adopt the same data (if any) as the corresponding Point. For example, would serve to determine which nearby areas are covered by each pharmacy in a municipality, and similar scenarios

• Objects selection: See the paragraph "About objects selection" above
• Table/Layer name: This setting defines the target Layer and data table name for the new Polygons. You can select an existing Layer in the drawing or you can write the name to create a new Layer. Areas of Influence objects will adopt the same data as the corresponding Points
  • Apply random colors to new Layers
• Create: Areas of Influence objects type, Borders or Polygons. The Polygons option allow you to select MPolygons as the type of object to use. This options is available on all compatible Autodesk products (even on vanilla, plain or basic AutoCAD) (AutoCAD 2013 and upper). The MPolygons can be defined by multiple rings, even including holes, as a single AutoCAD object
  • Fill areas using Hatches

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