`Matrix4.inverseTransformation`: misleading documentation
See original GitHub issueI don’t know who is defining “affine transformation” to be a composition of a rotation and a translation. Every definition I’ve found gives an affine transformation as an arbitrary (invertible) linear transformation followed by a translation.
However, inverseTransformation
returns subtly wrong results when, for instance, a non-uniform scale component is introduced.
The situation regarding this function is confusing, and could be improved:
- The documentation of
inverseTransformation
(and the cross-reference in the documentation ofinverse
) should be reworded to avoid using the term “affine transformation”. - Moreover, the function name is misleading. It does not invert all transformations. It should be called
inverseRotationTranslation
.
This issue was a real time-waster for me; hopefully the situation can be improved for future users.
Issue Analytics
- State:
- Created 2 years ago
- Comments:8 (8 by maintainers)
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Top GitHub Comments
@atlight @ebogo1 Would it make more sense if the documentation for
inverseTransformation
read something as follows?The documentation for
inverse
can be adjusted similarly:As for the alternative to
inverseTransformation
, maybe @ebogo1 let me know what you or others think of in the near future and I can work on replacing the name?Oh! Then perhaps we can change the wording of the documentation to say “Computes the inverse of the provided matrix assuming it is a rigid transformation.” However, it wouldn’t necessarily be true that “the upper left 3x3 elements are a rotation matrix,” right?We would have to reword it where “the upper left 3x3 elements are a rotation or reflection matrix,” or something like that?