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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::addParameterizationQuantity(std::string name, const T& coords, ParamCoordsType type=ParamCoordsType::UNIT)

Add a new parameterization quantity to the structure, defined per-point of the point cloud.

  • coords is the array of 2D UV coordinates at points. The type should be adaptable to an array of float-valued 2-vectors. The length should be the number of points in the point cloud.

  • type the default interpretation of the coordinate scale, see below

PointCloud::addLocalParameterizationQuantity(std::string name, const T& coords, ParamCoordsType type=ParamCoordsType::WORLD)

Add a new parameterization quantity to the structure, defined per-point of the point cloud.

This is similar to addParameterizationQuantity, but has preset settings for style and type which are suitable for local parameterizations about a point.

  • coords is the array of 2D UV coordinates at points. The type should be adaptable to an array of float-valued 2-vectors. The length should be the number of points in the point cloud.

  • type the default interpretation of the coordinate scale, see below

Parameterization Quantity Options

These options and behaviors are available for all types of parameterization quantities on any structure.

Styles

Several styles are available for how a parameterization is displayed.

The enum class ParamVizStyle has options for how parameterizations are visualized:

  • CHECKER: a two-color checker pattern
  • GRID: a grid with thin lines
  • LOCAL_CHECK: a checkboard over a radial colormap, centered around (0,0)
  • LOCAL_RAD: distance stripes over a radial colormap, centered around (0,0)
  • CHECKER_ISLANDS: a checkerboard where islands are colored according to the island labels integer, which must be given explicitly (meshes only)

The function SurfaceParameterizationQuantity::setStyle(ParamVizStyle newStyle) can be used to programmatically change the style.

Types

The enum class ParamCoordsType has options that control how parameter coordinates are interpreted:

  • 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

These enums can be passed as an optional third argument when a parameterization is registered.

Options

Parameter Meaning Getter Setter Persistent?
enabled is the quantity enabled? bool isEnabled() setEnabled(bool newVal) yes
style the visualization style (see above) ParamVizStyle getStyle setStyle(ParamVizStyle style) yes
checker colors two colors to use for checkerboards std::pair<glm::vec3,glm::vec3>getCheckerColors() setCheckerColors(std::pair<glm::vec3, glm::vec3> colors) yes
grid colors two colors to use for line and background of grid std::pair<glm::vec3,glm::vec3>getGridColors() setGridColors(std::pair<glm::vec3, glm::vec3> colors) yes
checker size the width of checkers / stripes, always used as a relative value, unless the coord tpe is UNIT double getCheckerSize() setCheckerSize(double val) yes
color map the color map to use for radial displays std::string getColorMap() setColorMap(std::string newMap) yes

(all setters return this to support chaining. setEnabled() returns generic quantity, so chain it last)