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Parameterization Quantities

A parameterization is a set of 2D coordinates associated with a surface, often referred to as “UV coordinates”.

Typically parameterizations are used on meshes (which is also supported in Polyscope!) but at times it may be useful to visualize a parameterization at the points of a point cloud.

Adding

PointCloud.add_parameterization_quantity(name, values, coords_type='unit', enabled=None, viz_style=None, grid_colors=None, checker_colors=None, checker_size=None, cmap=None)

Add a parameterization quantity to the mesh.

  • name string, a name for the quantity
  • values an Nx2 numpy array, coordinates at vertices/corners

This function also accepts optional keyword arguments listed below, which customize the appearance and behavior of the quantity.

Styles

Several styles are available for how a parameterization is displayed.

The viz_style option determines how parameterizations are visualized:

  • checker: a two-color checker pattern
  • grid: a two-color grid with thin lines
  • local_check: a checkerboard over a radial colormap, centered around (0,0)
  • local_rad: distance stripes over a radial colormap, centered around (0,0)

Types

The coords_type options determines how parameter coordinates are interpreted for scaling:

  • unit: UV coords are assumed to lie on the [0,1] interval
  • world: UV coords are assumed to be scaled like the world-space positions of the mesh

Parameterization Quantity Options

When adding a parameterization quantity, the following keyword options can be set. These are available for all kinds of parameterization quantities on all structures.

Keyword arguments:

  • enabled boolean, whether the quantity is initially enabled (note that generally only one quantity can be shown at a time; the most recent will be used)
  • coords_type string, one of 'unit', 'world' (see above)
  • viz_style string, one of 'checker', 'grid', 'local_check', 'local_rad' (see above)
  • grid_colors 2-tuple of rgb colors, used to color the grid visualization
  • checker_colors 2-tuple of rgb colors, used to color the checkerboard visualization
  • checker_size float, the size of checkers/grid/stripes
  • cmap string, which colormap to use

If not specified, these optional parameters will assume a reasonable default value, or a persistent value if previously set.