Passes
Reference
- Panel
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
Passes needed by the denoiser, for performing animation denoising in a second pass after rendering the entire animation. For still image denoising as part of the render process these are not needed. This also includes a render pass of the original combined pass before denoising. Note, the passes adapt to the denoiser selected for rendering.
Note
The Z, 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
- Render Time
Render time in milliseconds per sample and pixel.
- Sample Count
Number of samples/camera rays per pixel.
- 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.
- Shadow
Shadows from light objects. Mostly useful for compositing objects with shadows 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.
- 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.
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
Enable Cryptomatte Object render pass in the Passes panel, and render.
In the compositing nodes, create a Cryptomatte node and link the Render Layer matching Image and Cryptomatte passes to it.
Attach a Viewer node to the Pick output of the Cryptomatte node.
Use the Cryptomatte Add/Remove button to sample objects in the Pick Viewer node.
Use the Matte output of the Cryptomatte node to get the alpha mask.
See also
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.
Combining
Cycles
All these lighting passes can be combined to produce the final image as follows:
Eevee
The passes can be combined to produce the final image as follows:
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.