The Zone of Theoretical Visibility (ZTV) tool was designed to assess the visual impact of proposed developments within urban settings. It employs line-of-sight calculations to identify areas from which a building can be seen throughout the city. This feature is crucial for urban planners, architects, and developers, providing invaluable insights during the early stages of planning to evaluate and mitigate potential visual disturbances to the cityscape.

Standalone model configuration

The ZTV tool is designed to analyse single structures independently. Models incorporating multiple buildings or clusters cannot be accurately assessed with this tool as it is optimised for individual buildings.

Single mesh

For effective use of the ZTV tool, it is crucial to merge all parts of your model into a single mesh. This integration is necessary because the ZTV tool can only select and analyse one mesh at a time. Merging the model simplifies the tool’s processing and ensures that the analysis encompasses the entire structure uniformly.

Model optimisation

Users can import their own models for ZTV analysis, provided they are properly prepared. Often, architectural 3D models are overly detailed, containing numerous vertices for each window, wall, and beam, which the ZTV tool uses for calculations. Excessive vertices can significantly prolong processing times and potentially corrupt the results. If optimisation and simplification prove insufficient to expedite the process, we suggest creating a simplified massing model specifically for ZTV analysis (for example, using VU.CITY Create Tool).

Facade segmentation

Each model must have its facades segmented by floor to facilitate precise line-of-sight calculations. This segmentation allows the ZTV tool to accurately determine visibility from various angles and distances, crucial for assessing the visual impact within an urban landscape.

Suitable geometric composition

Facades within the model should be composed of triangles or quadrilaterals (tris or quads). It is critical that these shapes are split by floor to maintain the integrity of visibility calculations. Models that feature long polygon faces extending across multiple floors compromise the ZTV calculation’s accuracy because they do not reflect the physical breaks between storeys that influence visibility.

• ZTV polygons