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 to 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.
It is possible to add any number of layers, each set to output any complementary values to the Beauty image. These are derived from variables computed inside shaders and are commonly called Arbitrary Output Variables (AOVs). Example of layers are: 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. These layers can be useful for compositors to have many options while composing the final image. Refer to AOV Selector for further details on supported AOVs.
Layers can not only be generated using different AOVs, they can also:
- Have different camera angles. This is very powerful for fast simultaneous multi-camera rendering (for 3D stereo for example).
- Contain a different subset of objects in the scene. These are more advanced options and are described in the Layers Advanced.
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.
The Image Layers group
Global Options
Specifies the default file location for the image layers. By default, the location is based on the scene name, the render pass name and the AOV name. See File Path Expressions for details on how it is possible to construct relative paths and paths containing dynamically expanded tokens.
Default Image Format
Specifies the default file format for the image layers, including the bit depth. The default is 8-bit TIFF files. Many formats are supported and each have specific requirements as to what bit depths are supported. Refer to Image File Formats for more details.
Batch Output Mode
Each image layer have a file output toggle controlling wether it should be saved to file (this is explained in details below). Since these toggles may be manipulated frequently while working interactively and may be forgotten in a OFF position when sending the rendering on a render farm using the Maya Batch command line, the Batch Output Mode controls wether these toggles should be ignored (overridden) when rendering in batch mode. This option is useful to make sure all image layers are saved when rendering using the Maya Batch command line, regardless of the status of the file output toggle. The options are:
Enable file output as selected | Indicates to output the image layers to file (in batch mode) only if their corresponding file output toggle are selected. This is the default, it follows the same behaviour as in interactive mode. |
Enable all file output and selected JPEG | Indicates to ignore (override) the file output toggles and request that all image layers be saved to file when in batch mode. With regard to the output of a JPEG file, only those that are selected will be outputted to file (meaning the Batch Output Mode have no overriding effect to the JPEG output toggle and those are outputted only if enabled, wether in batch or interactive mode). |
The Interactive Output Mode allows to globally control the behaviour of the file output toggles while working during an interactive session. The options are:
Enable file output as selected | Indicates to output the image layers to file (in interactive mode) only if their corresponding file output toggle are selected. This is the default behaviour. |
Disable file output | Indicates to disable the output of the image layer to file (in interactive mode). Both the regular and JPEG file output toggles will be ignored. This is useful while working interactively and displaying image layers on screen only and to ignore the file output toggle (and possibly let them be used for batch mode only). |
Enable file output only for selected displays | This is an hybrid option. While working interactively, one may be interested to output to file only those image layers that he is actively working on; those that are selected to be displaying on screen. With this option, the image layers will be saved to file only if the display on screen toggle in selected. |
List of Layers (AOVs)
By default, the list is populated with only one image layer, the RGBA ("Beauty") layer.
List of Layers (AOVs)
Each layer can be selected to be displayed on screen or be saved to file or both. They can be saved in the specified format and also simultaneously in JPEG (similar in concept to a digital camera that can save simultaneously a RAW and a JPEG image). These outputs (display on screen and save to file) for each layer is controlled using three toggles located left of the layer name in the list. If no output toggles are selected, the image layer with its AOV is inactive.
display on screen | Enables the display of the image layer in a window on screen. The selection of which window (i.e. which application) |
file output | Enables the output of the image layer to file using file format and location specified by the Default Image Filename |
jpeg output | Enables the output of the image layer as a JPEG. The file location is the same as specified for the standard file, |
If all three toggles are selected, the image layer will be outputted simultaneously in a screen window, on file and as a jpeg.
Below the list of layers there are four buttons:
Add...
For adding layers. The AOV Selector will pop for selecting one or more AOVs.
Note: There is currently a problem with the AOV Selector: when selecting a new AOV in the AOV Selector and pressing OK, the ones already present in the List of Layers (AOVs) are removed. As a temporary work around, simply make sure you select in the AOV Selector these AOVs you already have in your List of Layers (AOVs) before you press OK. This way they will remain. (You can make multiple selections in the AOV Selector using the modifier keys).
Remove
Select one or more layers in the list to remove these. Note that the RGBA ("Beauty") layer can not be removed.
Duplicate
Select a layer in the list to duplicate it. You can then change some of the per layer attributes for the duplicated layer (otherwise you simply end up with exactly the same Layer/AOV without any difference).
View...
Select a layer to view it. This opens the Image Filename for that layer in a viewing application. Refer to The 3Delight Preferences for how to select which application should be launched.
Per Layer Attributes
When selecting a layer in the list of layers, the following list of attributes are available (below the Add/Remove/Duplicate/View buttons). These are per-layer attributes. Some and explained in Advanced and Outlining. Refer to the Layers Advanced for a description of these advanced attributes.
Group of attributes for a specific Layer
Image Filename
To override the Default Image Filename. The options are "Default" to use (not override) the Default Image Filename and "Custom" to specifies a custom filename for the selected layer. When default is selected, the complete expanded filename is listed just below (expanded from the token).
File Format
To override the Default ImageFormat. The options are "Default" to use (not override) the Default Image Format and "Custom" to specify a custom file format, including the bit depth.