I haven't got 6.3 in front of me but does the PlanarTracker add anything into the mix to make this easier? I seem to remember it outputs a 4*4 matrix for the planar track which is essentially a corner pin but I'll admit I need to look more closely at it.
On 21 August 2011 23:40, Pete O'Connell <[email protected]> wrote: > Thanks a lot Ivan. I'll have a play around with that tonight. > > Cheers > Pete > > > On Mon, Aug 22, 2011 at 3:57 PM, Ivan Busquets <[email protected]>wrote: > >> 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 >> > > > > -- > Pete > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >
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