23.01.2024 – CG
Week 13 – Understanding CG Rendering: AOVs and Passes
In the realm of Computer Graphics (CG), the understanding of AOVs (Arbitrary Output Variables) and various passes is crucial for achieving the desired visual outcome.
AOV (Arbitrary Output Variables):
- AOV information is encapsulated in passes or channels within an EXR file.
- Utilize the Shuffle node to extract the desired channel from the EXR file.
Rules for Rebuilding CG Assets:
- Always Plus Lights: Combine passes like Diffuse, Indirect, Specular, and Reflections.
- Always Multiply Shadows: Multiply passes like Ambient Occlusion (AO) and Shadows.
- Each pass should undergo individual grading, with the option for a final overall grade if necessary.
Types of Passes:
- Beauty Rebuild Passes:
- Aimed at recreating the beauty render.
- Material AOVs: Adjust the material attributes (shader) of objects in the scene.
- Light Groups: Fine-tune individual lights in the scene.
- Data Passes (Helper Passes):
- Utilities: Combined with tools to achieve effects like defocus, motion blur, re-lighting, etc.
- IDs: Create alphas or mattes for different areas of the render.
LayerContactSheet node:
- Use the LayerContactSheet node to create a comprehensive image showcasing all channels present in an EXR image.
- Enable ‘Show layer names’ to display the name of each channel.
Pass Adjustment with Shuffle node:
- Adjust each pass using the Shuffle node by separating and merging them.
- Ensure consistency between the original image and the merged image during this process.
*Tip: To replace a node, use Ctrl+Shift and drag the desired node onto the old one for quick replacement.