Hi Pete, It's very possible, but probably easier to do it in Python than using expression-links. Have a look at the nuke.math.Matrix4 class, and its mapUnitSquareToQuad() method.
I have a function somewhere to feed the transformation of a CornerPin node into the "matrix" knob of a roto/rotopaint node that would probably fit the bill for this too. I can try to dig that up if you're interested, but it would roughly consist of the following steps: 1 - Get the coordinates of the 4 "TO" corners from your cornerpin node. 2 - Build a "TO" matrix using mapUnitSquareToQuad(to0.x, to0.y, to1.x, to1.y, ...) 3 - Get the coordinates of the 4 "FROM" corners from your cornerpin node. 4 - Build a "FROM" matrix using mapUnitSquareToQuad(from0.x, from0.y, from1.x, from1.y, ...) 5 - The final transformation matrix should be => to_matrix * from_matrix.inverse(). Then you can use that to fill in the matrix knob in a gridwarp, a roto node, etc. Not the best example, but if you want some more info on how to use nuke.math.Matrix4.mapUnitSquareToQuad(), have a look here (towards the end of the page). http://www.nukepedia.com/written-tutorials/using-the-nukemath-python-module-to-do-vector-and-matrix-operations/page-4/ Hope that helps. Cheers, Ivan On Sun, Aug 21, 2011 at 10:24 PM, Pete O'Connell <[email protected]> wrote: > Hi does anyone know if it is possible somehow to convert cornerpin values to > a 4 by 4 matrix? Seem like it would be useful for the new Gridwarp and > Splinewarp nodes. > Thanks > Pete > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > _______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
