Hello, Actually, the effect is live version of "perspective" extension. The input is rectangle with modifiable by user nodes (which is originally generated from the object bounding box), the result - the object would be inscribed into modified rectangle, so it would look like in perspective. I am not aware if this problem has a solution based on some kind of generic coordinate transform formula, which could be applied to the whole Piecewise object, so I use my own solution of the problem based on straight-forward linear geometry, which calculates new position for each object's point and then tries to apply this value to the original point - as if the user used "node editor" tool to move points to the places where he wants to. I can try to describe the algorithm in more details if that makes sense. I know there is experimental perspective_path live effect which also works with perspective, but when I tried it, it appeared that it works in some different way - it does not use bounding rectangle to setup perspective, but relies on object resize/movements instead, so this is not what I need exactly. I also looked at the perspective.py code, but it seems that python extensions work in a bit different way than live effects, so I could not neither reuse it as is, nor understand its formula basing on source code without comments. thank's Anton