ExCodecs.Spatial.Transform (ex_codecs v0.2.3)

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

Reserved for future use. No shipped codec reads or writes Transform fields today. The module is provided so that formats which embed pose metadata (e.g. EXCP v2) can use a shared type when that support lands. 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}