Custom Geometry

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Custom geometries of San Francisco in the Tygron Platform

Custom Geometry is an item that stores 3-dimensional models (3D Models), which are coordinate based representations of Building surfaces. Optionally, these surfaces can be textured. This representation can be visualized in the 3D Visualization as an alternative to the default 3-dimensional representation of buildings generated by the Tygron Platform. During a single-, multi- or test-session, custom geometries shape can not be altered by users.

Representation

Custom geometry store data in a float array. The data stored is a set of triangle definitions: 3 Vertex definitions:

  • 3 floats representing a vertex coordinate: (x, y, z)
  • 2 floats representing texture coordinates: (tx, ty)

and 1 normal definition:

  • 3 floats representing normal coordinates: (nx, ny, nz)

Together 18 float values forming a triangle.

3D Model of Buildings

Buildings can link to one or more Custom Geometries using CGLinks. CGLinks store the id of the Custom Geometry Item, as well as whether it is the primary Building referencing this Custom Geometry. Custom Geometries are only placed for buildings in the 3D Visualization when that building is the primary referencer.

If a Building references any Custom Geometry, the default 3D Model of the building, that is mostly determined by its function, will not be visible.

These two points make sure that a set of lined up Buildings can be represented by one Custom Geometry, with one Building being the primary references and the other buildings not showing the default 3D Model.

Adjusting any visual property of the building will result in the removal of the Custom Geometry from the Building, even if it is not the primary referencer. This makes sure that adjustments made to the Building are clear.

Geometry Color and Offset

Custom Geometries in the 3D Visualization can be given an override color using the Building Attribute: GEOMETRY_COLOR Additionally, the datum (height) of the Custom Geometry might not be correct. This can also be override using the Height offset (Function Value).


Notes

See also