Overview
Using the Image Layers group of attributes the user specifies one or several layers of images to output simultaneously from the rendering process. Each can be set to be displayed on screen (in a window) or be saved in a file or both. By default, the Image Layers group of attributes is setup to output only one image layer: the RGBA components representing the main image, also commonly referred to as the Beauty. And it is setup to be displayed on screen and saved in a file.
It is possible to add any number of layers, each set to output any complementary information to the Beauty image, such as:
- Variables computed inside shaders, commonly called Arbitrary Output Variables (AOVs), such as depth values associated to the Beauty image, original color of surfaces (without the effect of the lighting), the specular and diffuse shading components of the Beauty image. Refer to AOV Selector for further details on supported AOVs and how to define custom ones.
- Contribution of individual or group of lights to the Beauty image.
- Any number of arbitrary masks derived from objects and/or materials.
Such layers can be useful for compositors to have many options while composing the final image and/or rapidly establishing the right light balance.
Layers can not only be generated for different AOVs, Lights and Masks, they can also:
- Have different camera angles. This is very useful for fast simultaneous multi-camera rendering (for 3D stereo for example).
- Contain a different subset of objects in the scene.
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All the layers are rendered simultaneously. Adding many layers do not generally increase rendering time significantly. This is different and not to be confused with the 3Delight for Maya functionality of Render Passes. Those are processed sequentially and can produce totally different output from one pass to another. |
| Warning |
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Windows only: Writing to disk many Image Layers may result in a performance bottleneck on Windows file systems. This is not the case on more efficient file systems such as Linux (ext4) and MacOSX (hfs+). |
| Tip |
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Multi-Layer EXRs: to write all Image Layers in the same EXR file, simply set the exact same Image Filename. In the screenshot below this would imply removing the
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