To provide an exploratory means, the results of the user's movement (or actions) have to be almost immediate. Real-time performance is achieved when the graphics scene is processed at a speed of at least 10 frames per second.

The objects that populate the virtual environment are described in a three-dimensional space (geography)&action=edit&redlink=1 "Three-dimensional space (geography) (not yet written)"). Any three-dimensional object is made up of points and polygons, with various properties of behavior and appearance. Due to the variability in complexity of virtual scenes, graphics performance is generally expressed in polygons rendered per second.[1]​.

Since the number of polygons that can be represented in real time is limited, there is a technique called level of detail (LOD), which is used to manage the complexity of the scene depending on the position of the observer. The objective is to maximize the quality of the image while maintaining the frame rate sufficient to perform an immersive tour, knowing that the size of the triangle and the resolution of the texture should vary inversely with the distance from the point of view.

LOD algorithms for representing large surfaces of terrain often rely on quadrangular tree representations for both terrain and textures. Typically, several different representations are precomputed, stored on disk, and loaded as needed.[1]​.

When, due to their nature, objects cannot be precomputed, another technique called "successive refinement" is used. In this case, when the user is interacting with the object, only a rough representation is displayed, and the new model is calculated on the fly. When the system is idle, system resources are used to refine the object representation. In the case of terrain representations, it is common to use a mathematical technique called wavelet decomposition to allow multi-resolution updates.[1]​.

The idea of ​​virtual GIS is the integration of GIS functionality (spatial queries and analysis) in a virtual environment. The inherent ability of virtual environments to produce "cognitive virtual maps" make it an appropriate platform for spatial exploration. Regular/hierarchical meshes or irregular triangular networks (TIN) of altimetry data, obtained from digital elevation models, with overlaid textures, usually derived from aerial photographs, satellite images or more abstract GIS layers (land use, winds, vegetation, aspect) constitute the most fundamental element of any virtual environment.[1]​.

The use of distributed virtual environments for computer-assisted collaborative work[3] constitutes a collaborative virtual environment. There is simultaneous multi-user access and rendering in the shared virtual environment. In this simulated networked environment, two or more users manipulate visual displays and exchange information through rich multimedia content. This evolution of the original concept has found a solid foundation in environmental sciences and urban planning, fields that are typically the main users of GIS.[1]​.

To provide an exploratory means, the results of the user's movement (or actions) have to be almost immediate. Real-time performance is achieved when the graphics scene is processed at a speed of at least 10 frames per second.

The objects that populate the virtual environment are described in a three-dimensional space (geography)&action=edit&redlink=1 "Three-dimensional space (geography) (not yet written)"). Any three-dimensional object is made up of points and polygons, with various properties of behavior and appearance. Due to the variability in complexity of virtual scenes, graphics performance is generally expressed in polygons rendered per second.[1]​.

Since the number of polygons that can be represented in real time is limited, there is a technique called level of detail (LOD), which is used to manage the complexity of the scene depending on the position of the observer. The objective is to maximize the quality of the image while maintaining the frame rate sufficient to perform an immersive tour, knowing that the size of the triangle and the resolution of the texture should vary inversely with the distance from the point of view.

LOD algorithms for representing large surfaces of terrain often rely on quadrangular tree representations for both terrain and textures. Typically, several different representations are precomputed, stored on disk, and loaded as needed.[1]​.

When, due to their nature, objects cannot be precomputed, another technique called "successive refinement" is used. In this case, when the user is interacting with the object, only a rough representation is displayed, and the new model is calculated on the fly. When the system is idle, system resources are used to refine the object representation. In the case of terrain representations, it is common to use a mathematical technique called wavelet decomposition to allow multi-resolution updates.[1]​.

The idea of ​​virtual GIS is the integration of GIS functionality (spatial queries and analysis) in a virtual environment. The inherent ability of virtual environments to produce "cognitive virtual maps" make it an appropriate platform for spatial exploration. Regular/hierarchical meshes or irregular triangular networks (TIN) of altimetry data, obtained from digital elevation models, with overlaid textures, usually derived from aerial photographs, satellite images or more abstract GIS layers (land use, winds, vegetation, aspect) constitute the most fundamental element of any virtual environment.[1]​.

The use of distributed virtual environments for computer-assisted collaborative work[3] constitutes a collaborative virtual environment. There is simultaneous multi-user access and rendering in the shared virtual environment. In this simulated networked environment, two or more users manipulate visual displays and exchange information through rich multimedia content. This evolution of the original concept has found a solid foundation in environmental sciences and urban planning, fields that are typically the main users of GIS.[1]​.