EXRs and overscan - NUKE vs FLAME

Flame Flame Questions
1

Quick question:

Done undistort in nuke which currently has better tools for that… It generates an EXR preserving the resolution and overscan from the undistorted is kept in within the DATA WINDOW… so DISPLAY WINDOWS is 3424x2202 (example of ALEXA 3.4k opengate) and DATA WINDOW is (3494X2248).

I need to bring this file, rename and drop in a different folder. Whenever I bring this EXR into flame as DISPLAY WINDOWS as I want to keep the resolution on my source and try to re export this it seems that once flames do the import it loses the overscan. Is there any solution for this?

Bruno

2

I believe not. In my experience, flame is wysiwyg.

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3

Normally, the workflow within Nuke is quite straightforward as Nuke can store pixels and data outside of the native format using a bounding box that expands and contracts as needed. So normally the workflow in nuke doesn’t worry about the edges of the comp/plate being cut off by the BowTie effect because when you re-apply the distortion it pulls the edges back into frame from the bounding box.

However if you need to export undistorted plates from Nuke, then you must export an oversized plate containing the full bowtie effect to keep all of the pixels.

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4

You need to add a reformat to bbox node in nuke then you get a new format that includes the bbox in the display area. as people have said before .

reformat to bbox is a custom node but you can just do reformat node set to box and add bbox.w and bbox.h into a expression for witdh and height.

Same applies when you give out the backplateplate for CG rendering basically baking in the overscan as you said.

I believe the new nuke lensdistortion(nuke 12.2? ) has a option to reformat to the bbox format even.

Dont forgett to adjust your filmback size to account for the now “wider” or “narrorwer” FOV depending on the distortion.

You can also export UV maps from nuke to flame to work on the distorted source material in flame thats saves you from rendering in nuke.