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

Reply via email to