Final Project Entry 3- Maya Workflow and Compositing

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 Before I opened up Maya, I had to create the HDRI image for lighting up my scene. So I opened up Photoshop and merged the individual images, masked out the sky region and applied an exposure and levels adjustment layer. I had to jump back and forth between PS and Nuke to check the color values of the sky region.

Then I created an new project window on Maya and imported all of my 3D assets, the tracking scene from Nuke and the HDR. I organised all of the point could locators and renamed the camera and locked it ot be safe. Then the HDR was added to the skydome and the Image plane was added as a background to the camera.


Then the 2 assets where brought in and I tested the animation and positioned the character on the ground plane. Keyframe animated the Statue descending from above. All of the textures were applied for the characters, I reused the base color for the subsurface scattering input. 

I created 2 render layers one for both for the assets and for the ground plane for receiving shadows. A shader override was applied to the ground plane in the first collection and an aiStandardSurface material was added as the override shader. Primary visibility was added as an absolute override to the ground plane in the Geo layer so that it won't be seen in the renders for that layer, and whereas the same was applied to the 2 assets in the shadow layer.


Along with the fundamental AOVs I added 3 more, a custom aiMotionVector, Z depth and SSS. So now it was time to test render to see if all the textures looked right, if the overrides work as intended and the alpha channels are correct for each layer. Thankfully everything looked perfect, now it was time for me to head to the Uni lab to render the whole final sequence out and to get some feedback from Johana there.

Beauty pass

Alpha Channel

Motion vector

AOVs

Took around 7-8hrs for the render to be complete. I then imported all of it into nuke and layered them, shadows above the backplate and CG assets above them all. 5 Shuffle nodes were added for each of the AOVs that may need grading and color correction. All of the individual Shuffle nodes were merged and the output was compared to the original beauty pass render to make sure all of the shuffles and merges were done correctly. An Unpremult was added before all of the shuffles and a Copy node was added after all the merges to copy the Alpha channel from the original render sequence and a premult node was added at the end. The shadows were barely visible and required some tweaking to make them more prominent and darker. I did some color corrections to the diffuse and sss AOVs, to make them pop a bit. Cranked up the red channel values for the sss AOV then realized this affected the cloth robe on the statue as well, so I used a Roto mask to constrain the CC on the sss AOV to just the female characters face.



Once I was happy how the assets looked and blended them into the scene, I added the ZDefocus node to add some depth of field. Set the focal point on the CG assets and increased the dof amount. Then moved on to adding some motion blur using the VectorBlur node. Set the uv channel to the custom Motion blur vector and the mv preset to Arnold. I only wanted a very subtle motion blur because the movements weren't fast or abrupt.

Depth of field Focal plane setup

Then the STmap was used to reintroduce the distortion onto the CG assets so they line up properly with the original backplate. Reformat node was added and the compositing of CG assets with the actual footage was complete.

Finally, the full composited video was exported using the Write node as a mp4 file with H.264 codec.

But I wasn't done yet, now I had to go to each of the steps and write out images for the breakdown video. First was the raw footage and its grading, then the lens distortion. then a short video sequence for the 3d camera tracking, then the CG assets on top of the footage, their shadows and at last the color corrections. Now, I finally done.



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