Several of the larger vfx companies recently have moved to a different vfx film-making practice which is a small but important concept change in how we work. This is the practice of positioning the shot plate and cg to the blocking or layout position earlier in the pipeline with a ‘layout camera’. Apart from the big vendors my experience is that most vendors dont yet get this. Previously vfx pipelines mostly receive the plates, do the matchmove and render the cg to fit the matchmoved plate. Then at the end of the pipe in composting we position the cg and plate to match the film’s rough edit according to the directors framing wishes. The model of using a layout camera is different as we position the plate to match the directors edit after matchmove but before CG renders.
There are several reasons why this might be a good idea:
- It’s an efficient use of labour. By making blocking decisions as early as possible it minimises vfx artists having to repeat work or throw it away.
- It’s an efficient use of the farm. It reduces rendering with large costly ‘overscan’ to allow space for repositioning later in the pipeline.
- It improves communication between the director and the vfx artists by making it easier for the vfx artists to view the image through the directors framing and so understand the shots narrative motivations.
- It improves communication between the director and the vfx artists by making sketch (or playblast) renders that are clearer to understand by the client, as it has the directors intended framing.
Many vfx supervisors hold off showing unfinished work due to the Director not being able to comment on it because the shot that’s being shown to them is unclear, or is a challenge to understand. This unfortunately leads to directors not making decisions early, one of several reasons that result in a deadline driven last minute changes. Directors need to understand how to make decisions at the earlier blocking, animation and lighting stages of a shots development. VFX is a film making craft just as set design or cinematography, and directors need to get the best out of us. Our responsibility is that, as film-makers, we are assisting the director, and so we need work in a clear way that a director can understand.
Using the node
Here is an example of a basic setup that uses a layout camera idea in Nuke: maya2nukeLayoutNode
It is very basic using Maya’s filmBack_Translate settings to define the position of the plate and then import those values into Nuke via an exported locator/axis. To calculate the values correctly it also requires the matchmove and render camera from Maya. Here are the values that adjust rotation/position/rotation/scale in maya:
- filmback.filmTranslateH
- filmback.filmTranslateV
- filmback.filmRollValue
- filmback.postscale
Link these values to a locator and export as fbx or whatever. Locator links to above values:
- translateX = camera.filmTranslateH
- translateY = camera.filmTranslateV
- rotatetX = camera.filmRollValue
- scaleX = camera.postscale
DIY Alternatives:
If you don’t need scale or rotation, the easiest way to do this is not to use this method but alternatively use the filmOffSet settings in Maya as they import natively into Nuke via fbx2010 (without having to use an axis node as nuke imports in filmOffset values) and then use this equation: (thanks dekeKincaid & ivanBusquets) window translate
- u: (2/haperture)(mayaFilmOffset.x*25.4) window translate v: (((root.format.h/root.format.w)*2)/vaperture)(mayaFilmOffset.y*25.4)
-If you were developing a pipeline you might do all this in a more sophisticated way; my recommendations would be either bake the data into an exr and get it from there, hackIvan’s abc Importer, or develop a layoutCamera in Nuke that exports a matrix with exr and use that in nuke (this would allow for full cornerPin type translates for perspective cheats/skews).
current stable beta release :Nuke tool to Copy and paste (read me license)
This node is in beta and has not been thoroughly tested in an production environment. Use at your own risk.
To improve this tool active development release is here (once it is stable we can release it on nukepedia)
This node is in beta and has not been thoroughly tested in an production environment. Use at your own risk.
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