This is a for the sake of documentation [also explained in Nuke Master Classes 2009 on foundry website in great detail ]and for new Nuke artist to know about \,,|_ RELIGHT _|,,/ plugin that allows a little more control over 3d space in nuke with nuke 3d feature . I mean little don’t expect lighting a bad ass scene in nuke . lighting dude are still required to do a great deal of the work. ( by the way I am a lighting artist by birth, that’s not important here at all ) . Okay enough chatter… lets start I am going to use ARNOLD ” the awesome ness ” because its so much easier to do everything, you spend time lighting the shot and no time clicking buttons unlike done in mental ray [which i still respect ] and I would edit this post in future explaining how it is done in Mentalray.
This is how simple the scene is two sphere’s a light a camera and a arnold renderer.
I have assigned a aistandard shader and set to AOV to output Normal and point position passes. I have rendered a exr with all the passes as channels [ also provided in the zip file attached]. Relight is available in Nuke 6.0.4 [I think ??] onwards and its a hidden tool. You have to update your plugins to be able to see it. So on the toolbar to the left side in Nuke interface that says other, under that go to All plugins and select UPDATE. Once you have clicked it you have to navigate your self to allplugins option again and you see
alphabetically categorized tools. under R select Relight or press TAB and type relight to load the tool.
Relight node needs a few inputs before it can actually work, a scene camera of the lighting file [fbx format 2009 only], a material [created in nuke], a scene node to communicate light and relight node and normal pass and point position pass [which can be in layers or exr channels ]. Connection of channels, settings of relight options are explained in image below.
Now I have connected a phong material to the material input of the relight node, you can choose any one you like and also connect a directional light or a light of your choice to the scene 3d node in the Node graph. immediately you will a light effecting the 2d image with a dull bright light this light can be rotated in nuke 3d view selection or via option box of light. Rotating the nuke light will effect 2d image as if it were in a 3d world space.
You can merge the output of relight with rendered beauty as a normal pass and continue with the flow
pls note you can also see the 3d scene camera based point cloud for better control and accuracy in positing the lights with use of positiontopoint node . shown in image below and the nuke file attached
Please note this is a rough edit of the post, language and format will be corrected eventually.