3D GIS terminology

Available with 3D Analyst license.

Below are the most common terms you will encounter when using the capabilities of the ArcGIS 3D Analyst extension in ArcGIS Pro.


Base height

A feature's base height is the elevation at which it or its vertices are displayed in 3D space. Base heights can come from within the feature geometry (for z-aware features), an attribute value or expression, or a referenced elevation data source. Combinations are also supported, such as features that have a height relative to a surface. Base heights are also commonly referred to as elevation values.

Functional surface

A continuous, 2.5D surface representation, where all locations on the surface have only one elevation value, or z-value, per x,y coordinate. Functional surfaces are most commonly used to model terrestrial data representing the earth's surface, though they can also be used to model many other types of surfaces, such as bathymetric data, individual geologic strata, or statistical surfaces describing geographic concentrations. Terrain datasets, TINs, and raster DEMs are all examples of functional surfaces.


Textures, sometimes referred to as facades or materials, are the images that are pasted onto the sides of 3D models, such as 3D buildings. Textures are supported for multipatch features stored in the geodatabase only. Note that the source texture imagery is saved in the Shape column, together with the multipatch's geometry definition.


A z-aware object takes into account its elevation, or stored z-values. Features that are z-aware store their z-values inside their geometry in the geodatabase (or shapefile), while feature classes or feature datasets that are z-aware store the units and datum those z-values represent. Using the Catalog window, you can create new z-aware feature classes, as well as load data stored in a table or spreadsheet to create z-aware feature classes.

Level of detail (LOD)

The complexity of an object represented in a 2D or 3D view. Commonly in computer graphics, a feature's level of detail is reduced as it gets farther away from the viewer or by some other formula based on object importance, eye-space speed, or position. Reductions in LOD may involve generalizing textures applied to features or simplification of their geometry. Reducing feature complexity and detail improves rendering performance by decreasing the workload on the graphics pipeline. Generally, the reduction in detail does not noticeably reduce the visual quality of the view because the feature is in the distance or is moving too quickly through the view.


A method applied to 2D features to generate a 3D object when actual 3D features are not available. Extrusion is available for layers in the 3D Layers category in the Contents pane. It can be applied for many purposes, such as generating realism in a 3D view or enhancing statistical or attribute information such as population.


Draping is one example of how a layer can exist in 3D space by defining its role with respect to other layers. A draped layer uses other layers as its source for elevation, so it drapes itself over the other layer features, texture (if any), and terrain details.


Like draping, floating is another way to distinguish how a layer exists in its 3D space. In this case, floating is used to display layers that are not intended to be placed on the elevation surface, such as rasters, underground or aboveground utilities, aircraft, and atmospheric conditions (clouds). Floating layers usually define their height source separately from other layers in the 3D view; draped layers usually share the same surface data as other layers.

3D model

A 3D model refers to the representation of any three-dimensional object, stored as a digital collection of features, rules, or both, that can be displayed as a two-dimensional image through rendering. The object may be stored as a wireframe (composed of different geometric entities such as lines, triangles, and curved surfaces) defining the shell of an object or as a solid (composed of parametrically or explicitly defined 3D objects that are added to or subtracted from each other to form a more complex object). Three-dimensional models are used extensively in the world of computer graphics, such as in motion pictures, animation, medical visualization and simulation, architecture, engineering, industrial design, aeronautics, computer gaming, chemical engineering, and planning. These 3D models can be constructed manually through a variety of software packages, such as SketchUp, 3D Studio Max, and Revit. In addition, 3D models can be generated from a variety of other sources, such as 3D scanning (lidar, sonar, and so forth), or derived from analysis procedures. COLLADA is an example of a 3D modeling format commonly in use today. In ArcGIS, 3D models may be used to represent points in 3D space or stored as features in a multipatch feature class.


A multipatch is a type of geometry in ArcGIS designed to represent the shell of a 3D object. Multipatches are composed from a series of patches that store geometry, color, transparency, and texture information. The geometry the patch stores may be a ring, triangle, triangle strip, or triangle fan. The shell these patches form might represent a completely enclosed feature, such as a sphere, or an open feature, such as a sloped roof. Multipatches may be used as 3D symbols to represent points or stored in a feature class with attributes. Multipatches are commonly used to store geotypical 3D symbols such as trees, street lamps, and park benches, as well as geospecific features such as buildings, bridges, and subsurface geologic formations.


Caching is a mechanism for managing large amounts of data. It improves display performance and may reduce data load times by storing prerendered information.

The display cache for layers is a local disk cache that stores data of your layers to improve display performance for navigating a map or scene. Each layer can have an individual caching option specified. Group layers do not have caching options.

To set the display cache options, right-click the layer in the Contents pane, click Properties, and click Cache. These are the options available for caching.

Cartographic layer offset

A vertical offset applied to a feature layer for visual effect. Using the Layer Properties dialog box, you can move the entire layer up or down (in Z) by a constant value. There is no effect on the geometry of the features, as no data change is being applied. This method is typically used as a visualization technique to lift 2D features up in 3D, for example, to highlight important locations or landmarks that may be hidden in their true 3D location, such as fire stations within a 3D city. Layer offsets are unavailable when editing features in a 3D environment.


The project item used to display and work with geographic data in three dimensions. A scene can open as either a global or a local perspective. A scene can be converted to a map, and vice versa.

3D model marker symbol layer

3D Simple marker symbol, 3D Marker symbol, 3D character marker symbol.

Marker symbol anchor points

Offset, 3D placement, normalized origin offset.

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