2.3 Maps, 3D Scenes, and Map Frames

2.3 Maps, 3D Scenes, and Map Frames

ArcGIS Pro provides a unified visualization environment that handles traditional two-dimensional (2D) maps and three-dimensional (3D) scenes within a single project document (.aprx). Previously, legacy GIS workflows required separate desktop applications (such as ArcMap, ArcGlobe, and ArcScene) to manage 2D and 3D spatial data. In ArcGIS Pro, 2D maps and 3D scenes exist side-by-side, allowing seamless data integration, automated conversion, and dynamic linkage within publication-quality page layouts.

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1. 2D Maps vs. 3D Scenes

Spatial visualization in ArcGIS Pro is structured into two core visualization paradigms:

• 2D Maps: Represent geographic data projected onto a flat planar surface using $X$ and $Y$ coordinates. Symbology, labeling, and scale ranges operate within a 2D Cartesian plane.
• 3D Scenes: Render spatial data in a three-dimensional perspective environment incorporating $X$, $Y$, and $Z$ (elevation/height) coordinates. 3D scenes support terrain draping, feature extrusion, Z-aware geometry, lighting/shadow simulation, and camera tilt/heading controls.

Multi-Map Project (.aprx)
├── 2D Map (City Parcels - PCS State Plane)
├── 3D Local Scene (Campus Buildings - PCS State Plane)
└── 3D Global Scene (Flight Paths - GCS WGS 1984)

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2. Deep Dive: Local Scenes vs. Global Scenes

When creating or converting a 3D view, ArcGIS Pro requires selecting between a Local Scene and a Global Scene. Choosing the correct scene type is a critical exam topic.

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3. Converting 2D Maps to 3D Scenes

ArcGIS Pro simplifies 3D adoption by enabling automated conversion of existing 2D maps into 3D scenes.

Conversion Workflow:

1. Open the target 2D map view.
2. Navigate to the View ribbon tab.
3. Click the Convert dropdown menu and select either To Local Scene or To Global Scene.

Exam Key Point: Converting a 2D map does NOT modify or overwrite the original 2D map. Instead, ArcGIS Pro creates a duplicate, independent 3D scene item inside the project file (.aprx).

Layer Categorization in 3D Scenes

Upon conversion, layers in the Contents pane are categorized into two groups:

• 2D Layers: Features draped flat over the elevation surface (ground level).
• 3D Layers: Features extruded vertically by attribute values (e.g., building height fields) or assigned Z-aware 3D symbols (e.g., 3D trees or volumetric spheres).

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4. Elevation Surfaces & Terrain Modeling

In 3D scenes, real-world elevation is governed by Elevation Surfaces listed in the Contents pane beneath the 3D Layers group.

• Ground Surface: The primary elevation layer representing top-of-ground terrain. By default, ArcGIS Pro loads Esri's online WorldElevation3D/Terrain service. Users can replace or supplement this with high-resolution Digital Elevation Models (DEMs), Digital Terrain Models (DTMs), or Triangulated Irregular Networks (TINs).
• Custom Elevation Surfaces: Additional surfaces defined above or below the ground surface. For example, a geologist can add custom elevation surfaces representing underground aquifer strata, mine seams, or bathymetric seabed floors.

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5. Map Frames in Page Layouts

A Map Frame is a layout container that embeds a 2D map or 3D scene onto a printable page layout. A single layout can host multiple map frames pointing to different maps or scenes within the project.

Page Layout Document
+------------------------------------------------------------+
|  Main Map Frame (Regional Watershed - 2D Map 1:50,000)     |
|                                                            |
|                                                            |
|  +------------------------+                                |
|  | Inset Map Frame        |                                |
|  | (State Locator Map)    |                                |
|  | [Extent Indicator Box] |                                |
|  +------------------------+                                |
+------------------------------------------------------------+

Linking Map Frames & Extent Indicators

1. Extent Indicators: A visual box drawn on a secondary (locator) map frame that dynamically displays the geographic bounds of the primary map frame. If the main map frame is panned or zoomed, the extent indicator on the inset locator map updates automatically.
2. Map Frame Linking: Map frames can be linked mathematically so that panning or zooming one frame drives the extent of another frame. Linking options include:
   • Center and Scale Match: Keeps both map frames centered at identical scale ratios.
   • Center Match: Aligns map frame centers while allowing independent scales.
   • Scale Match: Forces identical scale ratios while allowing independent center panning.

Multi-View Synchronization

Within the workspace, analysts can view 2D maps and 3D scenes side-by-side. Selecting Link Views on the View tab synchronizes the camera extent in 3D with the 2D pan/zoom position, allowing dual-perspective spatial analysis.