Had a play with this today, based on ideas from Ben, Ivan's great matrix tutorial on Nukepedia, and a post from Ean Carr in 2011.
Example scene: http://pastebin.com/DAz4YJkE Python script: http://pastebin.com/nSF0HyvC Scene has 4 axis (arrows denote parenting): axis_parent --> axis_inverseparent --> axis_child axis_target axis_child and axis_target have the same transform values. You can rotate and translate axis_parent, run the script, it snaps axis_inverseparent to the origin, meaning that axis_child and axis_target align. I can't get scale to work, so for now all scale's have to be (1,1,1). Ben, I tried your idea of moving the pivot, which seemed simple and quick, but it only seems to affect the pivot for UI dragging, not the worldmatrix itself, so it didn't help. Maybe I was doing it wrong.. Anyway, thought this might be of interest, especially if anyone can work out the scale stuff and tidy up my clunky code. :) -matt Ivans tut: http://www.nukepedia.com/written-tutorials/using-the-nukemath-python-module-to-do-vector-and-matrix-operations/page-4?showall= Ean's post: http://forums.thefoundry.co.uk/phpBB2/viewtopic.php?p=22048&sid=88412f53cee91f1843d50af416f0347d On 12 December 2013 22:47, Ari Rubenstein <[email protected]> wrote: > Another way to look at it is this, let the projection camera move with the > axis, but also have the geo being projected on move as well. > > ------ > > - camera input connected to axis (all offset transforms only on this axis, > no change to camera at all) > > - place TransformGeo node under geo being projected upon (after your > project3D shader and/or assign material node) > > - hook transformGeo's axis input to the Axis ( TransformGeo should be > completely Zero'd out, inheriting all its transforms thru the axis input > only) > > - now your proj camera & geo will move and rotate with the single axis and > the projection will stay intact > > --------- > I agree though, a "Maintain offset " function like in Maya would be better! > > Ari > Blue Sky > > > Sent from my iPhone > > > On Dec 12, 2013, at 2:08 AM, Ben Dickson <[email protected]> wrote: > > > > Ahh, right.. I don't think it's easily doable in Nuke, but you can > > achieve a similar result to that GIF in a few ways: > > > > Simplest way is to use the pivot control in the axis: Connect an axis > > upstream of the camera, press ctrl+alt and shift it around where you > > want to pivot, then you can rotate the axis etc > > > > More complicatedly, you can do this, which is kind of a pain to setup > > (similar to what localaxis does, if not exactly): > > https://gist.github.com/dbr/7924086 > > > > > >> On 12/12/13 17:03, matt estela wrote: > >> Hmm, more like this, explained through the magic of gifs and imgur: > >> > >> http://imgur.com/9Cv62j7 > >> > >> Basically, when you parent in Maya, Maya assumes you want the child to > >> stay at its current location. Nuke doesn't. That's weird. > >> > >> > >> > >> > >> On 12 December 2013 12:45, Ben Dickson <[email protected] > >> <mailto:[email protected]>> wrote: > >> > >> Slightly hard to describe in writing, but I think this is what you > are > >> after, > >> https://gist.github.com/dbr/7921735 > >> > >> You parent an axis under the "shot camera", then you parent a new > camera > >> under this transform.. allowing axis's transform controls to move the > >> camera in "object-local" space > >> > >> The other way of doing it is > >> http://www.nukepedia.com/python/3d/localaxis/ > >> ..which essentially sets up an expression-linked version of the > >> transform node with all the parameters negated ("-transform" and > >> "1/scale" etc) and transform/rotation orders reversed. This puts the > >> object at the origin, then you can do an object-local and reapply > the > >> original transform > >> > >> It's definitely not as intuitive as Maya in this respect, and tends > to > >> feel like all the steps have to be performed backwards.. but it's > quite > >> "simple", all 3D transforms nodes are just transform matrices, and > they > >> all concatenate together. It's true for Axis nodes, TransformGeo, the > >> object's transform controls etc, and is also exactly how the 2D > >> transforms nodes concatenate > >> > >> It would be nice if there was an additional axis input, "object > local" > >> which would be like the "local matrix" control.. but I'm not sure > it'd > >> quite remove the desire for a Maya-like parenting system.. I guess > the > >> other way would be a TransformGeo-like node which could apply to an > Axis > >> or Camera (or I could be getting entirely confused) > >> > >>> On 12/12/13 08:24, matt estela wrote: > >>> In maya, if you parent one object to another, the default behaviour is > >>> for the child object to keep its current position. There's an > >> option to > >>> turn this off, but its rarely used. > >>> > >>> In nuke, the default behaviour is to not main the current > >> position, and > >>> snap to a new location as if the parent is the world origin. Is > >> there a > >>> way to make it behave like maya? > >>> > >>> I know there's tricks for meshes, but last night I stumped a few > >>> lighters in the department where I wanted to parent a camera to an > >> axis, > >>> but leave it in its current location, couldn't do it. > >>> > >>> We tried doing stuff like expressions that subtract the values of the > >>> parent at frame 1 from the parent transforms, kind of worked, kind of > >>> didn't. In the end I just went back to maya, baked keyframes, > >> exported a > >>> camera. > >>> > >>> I assume we're missing a trick... right? RIGHT??? > >>> > >>> > >>> -matt > >>> > >>> > >>> _______________________________________________ > >>> Nuke-users mailing list > >>> [email protected] > >> <mailto:[email protected]>, > >> http://forums.thefoundry.co.uk/ > >>> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > >> > >> -- > >> ben dickson > >> 2D TD | [email protected] <mailto:[email protected]> > >> rising sun pictures | www.rsp.com.au <http://www.rsp.com.au> > >> _______________________________________________ > >> Nuke-users mailing list > >> [email protected] > >> <mailto:[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 > > > > -- > > ben dickson > > 2D TD | [email protected] > > rising sun pictures | www.rsp.com.au > > _______________________________________________ > > 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 >
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