Expand description
Rigid transforms: the composition algebra placements reduce to.
IFC expresses position as nested IfcAxis2Placement3D inside
IfcLocalPlacement chains, plus IfcCartesianTransformationOperator for
mapped items. All of it collapses to a 4x3 affine transform, which is what
this module provides.
§Why 4x3 and not 4x4
The bottom row of an IFC transform is always [0,0,0,1]: there is no
projective component. Storing it would invite code that reads it, and a
non-affine transform in a building model is always a bug.
Non-uniform scale IS representable, because
IfcCartesianTransformationOperator3DnonUniform exists.
Structs§
- Transform
- An affine transform: a 3x3 linear part plus a translation.