Friday, 8 June 2012

Red Or Dead: Compositing

(This is an ongoing post as I have lost some of the Nuke scripts.)

Roles:
Producer
Co- Editor
Co- Compositing (shot 7, 8, 9, 10, 13, 14 and 15)


nuke comp process screenshots
grading with teddy/ finding the look
rendering efficiently; layer, render layers, passes
efficiently in nuke


Compositing with Teddy:

Me and teddy worked on the compositing for this project solely in nuke. Nuke scripts were passed back and forth so organisations and file naming conventions were essential.

For the shot number mentioned above I did the green screen keying, (hold out mattes and garbage mattes where necessary) and trying to mach of the look of the live action footage with the matte painted backgrounds. The backgrounds for each shot were created by Elliot Crutchley and Megan Smith while Teddy decided on the final look by adding grain, camer shake and  red/ purple grade to the final piece.


I only did the Lighting, Rendering, Compositing. Model was by Teddy.

shot 7
Shot 10
shot 13
shot 14
Shot 15


Nuke File Naming Conventions:
An older post on file naming conventions
do not use: colon, semi-colon, parenthesis, brackets, asterisks, ampersands, spaces, hyphen.
 only use: full stops (only one. But two maximum.), underscores.

Example:
‘lowercaseCapital_shot_number_Captital_Capital.externtions_###’

In Context:
redOrDead_shot__1__sequenceName.tiff_001
redOrDead_shot__1__sequenceName.tiff_002
redOrDead_shot__1__sequenceName.tiff_003

10 Ways to Composite More Efficiently in Nuke: (ongoing post)

1) Framebuffer
before you even reach nuke use frame buffer in maya to choose bit depth.
there is no point in rendering out color and specular highlight as full "RGBA 32bit floats" EXRs when "RGBA 16 bit tiffs" will do.

2) Composite while you render by creating a link between any 3D renderer and Nuke.

3)
nuke is a scanline based and prefers scanline based EXRs.
convert "tile based" EXR's from maya to a "zip scanline" EXR format  or faster compositing.

use the color space node to change the EXR gamma encoding to

Tell Nuke to ignore empty areas of the file being read.
using a bounding box such as a curve tool node (set to autocrop) will save nuke render times.

Premultiply
before gamma, offset and color correction unpremultiply the render. After doing gamma, offset and color correction then premiltiply the image again to retune it to correct edges.

1) Use the Layer Contact Sheets node to see various passes at the same time.
This is waaaaay faster than using drop down menue.

2) Don't use EXR files for eveything.
EXR's are a "per pixel interwesved
If an EXR file is more than 20 layers deep Nuke will start to lag like crazy.
Soem passes can be tiff, jpegs as you will not always need the 32bit Floating point bells and whistles.

2) Test composites when you test renders to build Nuke Script templates.
By doing test comps you can build Nuke templates for everyone to work with and speed up compositing in the long run. Obviously tweaks will have to be made but

3) Build Gizmoz to stop repetition

4) If you can do it in 8 nodes do it in 4

Precomp

5) make all compositing notes from annotated screenshots
6) python expressions (avoid expressions when you can)
7) learn shortcuts (link to shortcuts)
8) fine naming convetions






Here are few links to some good resources online. Some of them will seem to go over what I have just

Nuke Shortcut keys

Efficiency In Nuke:
http://www.nukepedia.com/written-tutorials/10-tips-to-optimising-nuke-and-creating-efficient-workflows/

Other Useful Websites On Nuke:
http://www.nukepedia.com/
http://thoughtvfx.blogspot.co.uk/
http://satheeshnuketutorials.blogspot.in/
http://www.learningnuke.com/
http://franzbrandstaetter.com/?cat=4

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