Reverse compound transformation

Hi there,

could I reverse a compound transformation?

So e.g. compound X:

move from A to B / Rotate with pi around center C / Orient from plane D to E

would become

Orient from plane E to D / Rotate with -pi around center C / move from B to A

Thanks.

Replies to This Discussion

Permalink Reply by phillip on September 18, 2012 at 6:14am

Would it be possible to modify somehow the TransformationMatrix to I get what I am looking for?

Permalink Reply by David Rutten on September 18, 2012 at 6:27am

There's two ways to go about this:

Use the Rhino transform matrix methods
Use the Grasshopper transformation methods

Since [1] is easiest, let's start there. There's a method that attempts to get the inverse of a Transformation matrix in the Rhino SDK. This approach does involve 'losing' the individual transformations that went into making the final transform, but you may not care about that.

See attached.

David Rutten

david@mcneel.com

Poprad, Slovakia

Attachments:

ReverseTransform.gh, 3 KB

Permalink Reply by phillip on September 18, 2012 at 7:25am

Thanks for the reply. This already very useful.

Yes, I guess I was looking for [2], because I wanted to try to use only parts of the reversed transformations. So it would be usefull to even have them split up and described.

Now I can SplitCompound - GraftList - ReverseTransformation -FlattenList - ReverseList to get the reversed StepbyStep-Transformation, though it just gives me "Generic" as information.

Permalink Reply by David Rutten on September 18, 2012 at 8:22am

Not all transformations can be reversed. PlanarProjection for example destroys 1/3 of the information. I can add some components for reversing transformation whenever possible though.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Henry Richardson on March 14, 2018 at 10:28pm