The Passes Tab

When you first open the Passes tab you are presented, by default, with the outputs for your Final pass. You can switch to existing passes, create new ones, or apply filters by clicking on the arrow next to the Pass window to access a pop-up window. Each pass has a separate tab for Pass Settings and Outputs.

The Outputs Sub-Tab

The default output of the Final Pass is, as you might expect, rgba, the color and alpha channels of a typical image. You can select other outputs, including "Custom" outputs by clicking on the arrow to the right of the output window.

The Outputs Sub-Tab also includes settings for the output Image Format, Channels, Filter, Filter Size, Dither, and Exposure. The defaults and options for these settings will change, depending on the output you have selected (e.g. the default image format for rgba is mayaiff, but for _shadow it is tiff). For more information on outputs, please see the Secondary Outputs (AOVs) section of the documentation.

The Settings Sub-Tab

The Pass Settings sub-tab allows users to define the caching behavior for the pass, as well as the render camera, object and/or light sets, the format of the pass's name, and a crop window. This sub-tab also provides controls for photon generation and a drop down for choosing to enable Depth of Field via the camera's settings or to disable DOF globally.

Additional settings for a pass can be added (or removed) via the Add/Remove Settings button in the Extra Settings section.

Auto-Updating Sub-Menus for Individual Passes

When a pass is selected in the Pass Window, the settings for that pass will appear in the Settings tab. In this example, the DeepShadow Defaults have been selected. The settings used for different passes are similar, so let's take a quick look at the DeepShadow settings.

Caching Behavior: Compute, Reuse, or straight-up Disable, yo.

Phase: Determines how often passes are computed. Every Frame causes passes to be computed every frame, which is preferable if the objects in a pass are changing from frame to frame. Otherwise, if objects in a map do not change through an animated sequence, Once per Job can be used, saving valuable rendering cycles.

Camera: Select an existing camera or create a new camera as the render camera for this pass.

Object Set: Select or create a set of objects to be included as "renderable" in this pass.

Camera Flavor: Applicable only for point lights, select a specific X, Y, or Z camera as "renderable", otherwise this is inferred from the light/camera settings.

Light Set: Select or create a set of lights to be included as "renderable" in this pass.

Resolution: Applicable only for point lights, select a resolution for the maps, otherwise this is inferred from the light/camera settings.

Shading Rate: Shading Rate controls two important factors. First, Shading Rate governs the quality of shaders. Smaller numbers mean the shaders must be evaluated at more places on the surface of the primitives. Second, Shading Rate governs how much detail is created on a per-pixel basis, and more detail means more work, requiring more hidden-surface evaluation and more memory.

Pixel Samples: As with the corresponding setting found on the Quality tab, "Pixel Samples" is used to control the amount of super-sampling around a pixel, though just for this particular pass. For speed, this can be set to zero, with the expected loss of image quality.

Motion Blur: Enables motion blur for the Deep Shadow pass. Note that this setting does not appear in the regular Shadow Defaults.

Ray Tracing: Enables ray tracing for this pass.

Default Surface Shader: Useful in special cases, like occlusion. Allows a single shader to be attached to all objects in a pass. By default this is "null".

Emit Surface Shaders: If surface shaders are needed in a pass, this setting can be enabled so that surface shaderswill be calculated. Turning this off causes surface shaders to be ignored, speeding up rendering calculations.

Emit Displacement Shaders: If displacements are needed in a pass, this setting can be enabled so that displacements will be calculated. Turning this off causes displacements to be ignored, speeding up rendering calculations.

Emit Light Shaders: If light shaders are needed in a pass, this setting can be enabled so that lights will be calculated. Turning this off causes lights to be ignored, speeding up rendering calculations. Lights aren't important in shadows, but are needed for reference images.

Emit Volume Shaders: If volume shaders are needed in a pass, this setting can be enabled so that volume shaders will be calculated. Turning this off causes volume shaders to be ignored, speeding up rendering calculations.

Deep Shadow Error/Deep Shadow SimplifyError: Allows users to specify error tolerance for lossy compression of deep texture files.