ExCodecs.Spatial.Transform (ex_codecs v0.2.0)

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Rigid/similarity transform metadata, not applied to points by this library.

Codecs may embed transforms in headers when a format supports it. Application of transforms is left to higher-level code.

Fields

  • :translation — {float(), float(), float()} Cartesian offset; defaults to {0.0, 0.0, 0.0}. Units match the associated spatial coordinates.
  • :rotation — {float(), float(), float(), float()} scalar-first {w, x, y, z} quaternion; defaults to identity {1.0, 0.0, 0.0, 0.0}. Unit length is not enforced.
  • :scale — float() uniform dimensionless scale; defaults to 1.0.

This module stores transform metadata but does not define composition order or apply transforms; consumers must follow the enclosing format's convention.

Example

iex> ExCodecs.Spatial.Transform.new(
...>   translation: {10, 0, -2},
...>   rotation: {1, 0, 0, 0},
...>   scale: 0.5
...> )
%ExCodecs.Spatial.Transform{
  translation: {10.0, 0.0, -2.0},
  rotation: {1.0, 0.0, 0.0, 0.0},
  scale: 0.5
}

Summary

Types

t()

Transform metadata with translation, scalar-first quaternion rotation, and uniform scale. See the module documentation for all fields, defaults, units and conventions, and a construction example.

Functions

identity()

Identity transform.

new(opts \\ [])

Builds a transform.

Types

t()

@type t() :: %ExCodecs.Spatial.Transform{
  rotation: {float(), float(), float(), float()},
  scale: float(),
  translation: {float(), float(), float()}
}

Transform metadata with translation, scalar-first quaternion rotation, and uniform scale. See the module documentation for all fields, defaults, units and conventions, and a construction example.

Functions

identity()

@spec identity() :: t()

Identity transform.

Arguments

None.

Returns

%Transform{} with zero translation, identity quaternion, scale 1.0.

Raises

None.

Examples

iex> t = ExCodecs.Spatial.Transform.identity()
iex> t.scale
1.0

new(opts \\ [])

@spec new(keyword()) :: t()

Builds a transform.

Arguments

  • opts — a keyword list with:
    • :translation — numeric {x, y, z}; defaults to the origin and is stored as floats.
    • :rotation — numeric {w, x, y, z} scalar-first quaternion; defaults to identity and is stored as floats.
    • :scale — number(); defaults to 1.0 and is stored as a float.

Returns

%Transform{}

Raises

Examples

iex> t = ExCodecs.Spatial.Transform.new(translation: {1, 0, 0}, scale: 2)
iex> t.translation
{1.0, 0.0, 0.0}