Manual Reference Rendering Menu Render Settings
Multi-Pass
Multi-pass rendering makes it easy for you to post-edit your renders in compositing software such as Adobe After Effects, Photoshop and Combustion. With multi-pass you can split the CINEMA 4D rendering into separate layers such as shadows, reflections, highlights and each separate light source. You can save the layers in RLA, RPF, Photoshop (PSD) and BodyPaint 3D (B3D) format.
Suppose you’ve rendered a complex movie and the reflections look too strong. With multi-pass, there’s no need to re-render the CINEMA 4D scene. Instead, simply reduce the opacity of the reflections layer in your compositing package. Or why not include alternative lighting setups in the same rendering? You’ll then be able to select the best setup during post-editing.
Multi-pass is ideal for trying out various lighting setups for your rendering The setups will be rendered more quickly as a single multi-pass file than as separate projects.
Use this option to enable or disable multi-pass rendering.
Channels
The Channels dropdown list displays the layers that may be included in the multi-layer rendering. It also contains various relevant commands. Use the Channels dropdown list to add layers to or remove layers from the selection list.
The items in the Channels dropdown list are:
Add Image Layers
Adds to the selection list all image layers that form the composite image. These layers are: Ambient, Diffuse, Specular, Shadow, Reflection, Refraction, Atmosphere and Atmosphere (Multiply). All the other image layers (see ‘The layers’, below) may be used for visual effects but are not actually part of the composite image.
If you have the Advanced Render module installed, Global illumination and Caustics layers are also added to the selection list by this command.
Add Material Layers, Add All
These commands are useful to plugin developers only.
Remove Selected
Removes the selected layers from the list.
Remove All
Empties the selection list.
Blend Channel
Creates a blended layer. For example, you can blend Shadow, Global illumination and Caustics as a single layer. After choosing this command, a dialog opens. Enable the channels you want to blend and click OK.
Object Buffer
This creates a mask layer for objects that use a specified ID number in their Compositing tags. After choosing this command, the Object Buffer dialog open. Enter the desired ID number and click OK.
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| The sphere appears in both object buffers since its Compositing tag has two IDs (ID=1 and ID=2). |
To assign an ID to an object, use a Compositing tag.
The layers
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The lower part of the Channels dropdown list shows the layers that you can add to the multipass rendering, a selection of which is illustrated above. These are RGBA Image, Ambient, Diffuse, Specular, Shadow, Reflection, Refraction, Global illumination, Caustics, Atmosphere, Atmosphere Multiply, Illumination and Depth (the remaining layers in the list — i.e. those whose names begin with ‘Material’, are of use to plugin developers only).
The Global Illumination and Caustics layers contain the effects created by global illumination and caustics and are of use only if the optional Advanced Render module is installed.
The RGBA layer is the complete image — the same image as with normal rendering. An alpha channel will be included if Alpha Channel is enabled on the Save page of the render settings.
The Ambient layer shows the illumination generated by an Environment object if used.
Atmosphere adds a layer for environment fog and volumetric effects such as volumetric light. Atmosphere (Multiply) can be used optionally with Atmosphere to help conceal objects that are behind the volumetric effects (a multiplied atmosphere layer is used).
Illumination adds a layer for the color and brightness of surfaces illuminated by light sources.
Depth adds a depth map — object surfaces are shaded in grayscale according to their distance from the camera. The closer a surface is to the camera, the darker its shading in the depth map.
The Depth channel defines the distribution of depth in the scene. This information can be used in compositing applications to create visual effects. Black parts represent the focus (Target Distance on the Camera’s Depth of Field page in the Attribute manager).
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| From top left to bottom left: Highlights (AR), Glow (AR), Specular, and Diffusion, each as a separate Post Effects pass. |
The Post Effects channel makes it possible to render a variety of post effects (PyroCluster, lense effects, vector motion blur, highlights, glow effects, glow) as separate passes.
Material Normal
Not to be confused with normal maps, these normal components are rendered as RGB (X = red, Y = green, Z = blue) without anti-aliasing. This is designed for compatibility with other applications.
Material UVW
This channel renders objects (without anti-aliasing), according to their UVW coordinates, in a green-red-blue gradient: U = red, Y = green, W = blue. Applications such as After Effects or Combustion can easily work with these files.
Motion Vector
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| A Motion Vector Multi-Pass. Left: A slowly rotating propeller; right: A propeller rotating faster. |
Motion Vector lets you output color-coded motion vectors. Depending on the direction of movement, each object pixel will be colored accordingly red=X; green=Y; blue is not used). Third party applications, such as ReelSmart Motion Blur for example, can calculate motion blur based on these colors. The maximum length can be defined using the Motion Scale setting (Render Settings... > Options page).
Ambient Occlusion
If you own the Advanced Render module you can generate an Ambient Occlusion pass for the entire scene, in accordance with the Ambient Occlusion options in the Render Settings.
Enable this option if you want the multi-pass image to be saved when you render to the Picture viewer.
If this option is enabled, all layers are saved in a multi-layer file. In addition, you must set Format on the Output page to Photoshop (PSD), RLA, RPF or BodyPaint 3D (B3D). If the option is disabled, CINEMA 4D creates a separate file for each pass using the Format setting on the Save page. A suffix is added to each of the filenames to differentiate them.
When rendering multi-passes with shadows switched on, slight artefacts such as bright lines may appear at object edges due to antialiasing. To prevent these artefacts from appearing, enable this option.
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| Enable Shadow Correction to prevent artefacts from appearing at the edges of objects. |
This option is only available if you have activated the Alpha Channel option in the Render Settings Save tab. Whether or not you activate Straight Alpha does not play a role.
With the Straight (Unmultiply Alpha) (Multi-Pass tab) option you define whether or not the corresponding multi-passes should be pre-multiplied with reference to the alpha channel that is saved.
Use Separate Lights to choose which light sources have their own separate layers.
No separate layers.
Each light has separate layers.
Separate layers for all lights whose Separate Pass option is enabled (Details page).
Use Mode to control how the diffuse, specular and shadow information is layered for each light source that has its own layers.
1 Channel: Diffuse+Specular+Shadow
Adds one blended layer for Diffuse, Specular and Shadow.
2 Channels: Diffuse+Specular, Shadow
Adds one blended layer for Diffuse and Specular, and one layer for Shadow.
3 Channels: Diffuse, Specular, Shadow
Adds one Diffuse layer, one Specular layer and one Shadow layer.
This is where you set the save path for the file.
Multi-layer files require much more space than single-layer files. Prior to rendering, check that you have sufficient storage space, especially when rendering multipass animations.
Here, choose the file format. For a multi-layer file, choose Photoshop (PSD), RLA, RPF or BodyPaint 3D (B3D).
This button is greyed out unless the format chosen has extra options. Click Options to access these.
Sets the channel depth to 8 bits or 16 bits or 32 bits.
If your chosen format does not support multi-layers, each layer will be saved as a separate file. If this option is enabled, the name of the layer, such as ‘_diffuse’ or ‘_refraction’, is added after the filenames.