Passes

Reference

Panel:

Scene ‣ View Layers ‣ Passes

Passes can be used to split rendered images into colors, direct and indirect light to edit them individually, and also to extract data such as depth or normals.

Data

Cycles

Include

  • Combined

    The final combination of render passes with everything included.

    Z

    Distance to any visible surfaces.

    Note

    The Z pass only uses one sample. When depth values need to be blended in case of motion blur or Depth of Field, use the mist pass.

    Mist

    Distance to visible surfaces, mapped to the 0.0 - 1.0 range. When enabled, settings are in World tab. This pass can be used in compositing to fade out objects that are farther away.

    Position

    World position of objects in the scene.

    Normal

    Surface normal used for shading.

    Vector

    Motion vectors for the Vector Blur node. The four components consist of 2D vectors giving the motion towards the next and previous frame position in pixel space.

    UV

    Mapped UV coordinates, used to represent where on a mesh a texture gets mapped too. This is represented through the red and green channels of the image. The blue channel is encoded with a constant value of 1 but does not hold any information.

    Denoising Data

    Includes Denoising Albedo, Denoising Normal, and a render pass of the original combined pass before denoising.

Note

The Z, Position, Object Index, and Material Index passes are not anti-aliased.

Indexes

  • Object Index

    Creates a mask of the object that can be later read by the ID Mask Node in the Compositor.

    Material Index

    Creates a mask of the material that can be later read by the ID Mask Node in the Compositor.

Debug

  • Sample Count

    Number of samples/camera rays per pixel, to analyze adaptive sampling.

Alpha Threshold

Z, Index, normal, UV and vector passes are only affected by surfaces with alpha transparency equal to or higher than this threshold. With value 0.0 the first surface hit will always write to these passes, regardless of transparency. With higher values surfaces that are mostly transparent can be skipped until an opaque surface is encountered.

EEVEE

Include

  • Combined

    The final combination of render passes with everything included.

    Z

    Distance to any visible surfaces.

    Mist

    Distance to visible surfaces, mapped to the 0.0 - 1.0 range.

    Normal

    Surface normal used for shading.

Light

Cycles

Diffuse

  • Direct

    Direct lighting from diffuse and subsurface BSDFs. We define direct lighting as coming from lights, emitting surfaces, the background, or ambient occlusion after a single reflection or transmission off a surface. BSDF color is not included in this pass.

    Indirect

    Indirect lighting from diffuse and subsurface BSDFs. We define indirect lighting as coming from lights, emitting surfaces or the background after more than one reflection or transmission off a surface. BSDF color is not included in this pass.

    Color

    Color weights of diffuse and subsurface BSDFs. These weights are the color input socket for BSDF nodes, modified by any Mix and Add Shader nodes.

Glossy

  • Direct, Indirect, Color

    Same as above, but for glossy BSDFs.

Transmission

  • Direct, Indirect, Color

    Same as above, but for transmission BSDFs.

Volume

  • Direct, Indirect

    Same as above, but for volumetric BSDFs.

Other

  • Emission

    Emission from directly visible surfaces.

    Environment

    Emission from the directly visible background. When the film is set to transparent, this can be used to get the environment color and composite it back in.

    Ambient Occlusion

    Ambient occlusion from directly visible surfaces. BSDF color or AO factor is not included; i.e. it gives a ‘normalized’ value between 0 and 1.

    Shadow Catcher

    Extra indirect light information collected by objects with the Shadow Catcher option enabled. Multiply this pass with existing footage using the Mix Node in the Compositor to add the indirect lighting information to the footage.

Note

Transparent BSDFs are given special treatment. A fully transparent surface is treated as if there is no surface there at all; a partially transparent surface is treated as if only part of the light rays can pass through. This means it is not included in the Transmission passes; for that a glass BSDF with index of refraction 1.0 can be used.

EEVEE

Diffuse

  • Light

    Direct lighting from diffuse BSDFs. We define lighting as coming from lights, the background, or ambient occlusion off a surface. BSDF color is not included in this pass.

    Color

    Color weights of diffuse BSDFs. These weights are the color input socket for BSDF nodes, modified by any Mix and Add Shader nodes.

Specular

  • Light, Color

    Same as above, but for specular BSDFs.

Volume

  • Light

    The scattering pass from volume objects or world.

Other

  • Emission

    Emission from directly visible surfaces.

    Environment

    Emission from the directly visible background. When the film is set to transparent, this can be used to get the environment color and composite it back in.

    Shadow

    Shadows from light objects. Mostly useful for compositing objects with shadow into existing footage.

    Ambient Occlusion

    Ambient occlusion from directly visible surfaces. BSDF color or AO factor is not included; i.e. it gives a ‘normalized’ value between 0 and 1.

Effects

EEVEE only

Bloom

The influence of the Bloom effect.

Transparency

Contain Alpha Blended surfaces, so they can be adjusted in the compositor and later mixed with opaque passes.

This pass only supports monochromatic opacity. Colored opacity will show differently than in combined pass.

Cryptomatte

Cryptomatte is a standard to efficiently create mattes for compositing. Cycles outputs the required render passes, which can then be used in the Blender Compositor or another compositor with Cryptomatte support to create masks for specified objects.

Unlike the Material and Object Index passes, the objects to isolate are selected in compositing. The mattes will be anti-aliased and take into account effects like motion blur and transparency.

Object

Render cryptomatte object pass, for isolating objects in compositing.

Material

Render cryptomatte material pass, for isolating materials in compositing.

Asset

Render cryptomatte asset pass, for isolating groups of objects with the same parent in compositing.

Levels

Sets how many unique objects can be distinguished per pixel.

Typical Workflow

  1. Enable Cryptomatte Object render pass in the Passes panel, and render.

  2. In the compositing nodes, create a Cryptomatte node and link the Render Layer matching Image and Cryptomatte passes to it.

  3. Attach a Viewer node to the Pick output of the Cryptomatte node.

  4. Use the Cryptomatte Add/Remove button to sample objects in the Pick Viewer node.

  5. Use the Matte output of the Cryptomatte node to get the alpha mask.

See also

Cryptomatte Node.

Shader AOV

Shader AOVs (Arbitrary Output Variables) provide custom render passes for any shader node components. As an artist this can be a good way to fix or tweak fine details of a scene in post-processing. To use Shader AOVs create the pass in the Shader AOV panel then reference this pass with the AOV Output shading node. Shader AOVs can be added or removed in the Shader AOV panel. In this panel is a list of all AOV passes; each AOV in the list consists of a Name and Data Type.

Active AOV Index

The name of the render pass; this is the Name that is referenced in the AOV Output node. Any names can be used for these passes, as long as they do not conflict with built-in passes that are enabled.

Data Type

Shader AOVs can either express a Color or a Value output. The Color type as the name suggest can be used for a color but also for normals. A Value type can be used for any single numerical value.

Light Groups

Cycles only

Light Groups provide render passes that only contains information from the lights within that group. Light Groups can be used to easily tweak the lighting color and intensity of specific lights without having to re-render the scene.

Active Light Group Index

The name of the render pass. This is the name that is used when adding World Shaders, Lights and Objects to Light Groups.

Lightgroup Sync

These operators are available in the menu to the right of the Light Group list.

Add Used Lightgroups

Adds all Light Groups to the View Layer that have been created elsewhere and have lights assigned to them.

Remove Unused Lightgroups

Deletes all Light Groups that do not have any lights assigned to them.

Combining

Cycles

All these lighting passes can be combined to produce the final image as follows:

../../_images/render_layers_passes_combine.svg

EEVEE

The passes can be combined to produce the final image as follows:

../../_images/render_layers_passes_eevee-combine.svg

Known Limitations

  • Alpha blended materials are not rendered in render passes except the combined pass. Use the Alpha Clip or Alpha Hashed as Blending Mode to render transparent materials in render passes.

  • Depth of field is not rendered in render passes except the combined pass. It is possible to add the depth of field back in the Compositor using the Defocus node.

  • EEVEE render passes exclude parts of the BSDF equation. Shader to RGB is not supported as it needs the full BSDF equation.