Trafo transformations

[luithefirst]

Trafo does not directly allow to perform a transformation, instead the user needs to explicitly take Forward or Backward and perform the transform using the matrix. This also requires considering that direction vectors need to be transformed with the inverse transposed matrix. I find myself often ignoring this when I know that the Trafo does not have a scale but actually this is a bad practice, especially since it would not cost anything to do it properly.

My suggestion is to add transform methods directly to Trafo that where the versions for Dir internally make an inverse transposed transform:

• TransformPos: Forward.TransformPos
• TransformDir: Backward.TransposedTransformDir
• InvTransformPos: Backward.TransformPos
• InvTransformDir: Forward.TransposedTransformDir
• (Transform with V4d for completeness)
• (InvTransform with V4d for completeness)

I'm pretty sure that this has been discussed at some point, but I can't remember any details. Do you see any issues?

Those direct transform methods would make Trafo equivalent to Euclidean and other transforms. A lot of code would get much more robust and easier to read. It would make the awesomeness of Trafo work for you behind the scene without needing to worry about and not always when you want to use a Trafo reminding you that there are two matrices internally.

I would be happy to see this extension in a future Aardvark version.

[hyazinthh]

Added in https://github.com/aardvark-platform/aardvark.base/commit/5f25d838eb9145670fc8e20266f1e1b16671d38b

[luithefirst]

Thanks for the addition, already in use, everything fine!

[luithefirst]

(Inv)TransformPosProj is missing