Sample workflow for multi-render passes

This sample workflow illustrates how to do the following:

• Use the Render Layer Editor to create render pass contribution maps.

  Although this step is optional, render pass contribution maps give you finer control over light and objects and their passes relationship. For example, you can use pass contribution maps to easily create a diffuse pass for a specific object that is illuminated by a specific light.

• Create render passes for each render pass contribution map.
• Render the scene and create the subfolders and filenames for the rendered images.
• Group render passes into render pass sets and render the set.

Note:

For a list of available passes, and a list of shaders that is currently supported by the multi-render pass workflow, see Multi-render passes.

Note:

The multi-render pass feature is supported for the mental ray renderer. The rendering API allows other 3rd party renderers and custom renderers to support it moving forward.

Rendering with render pass contribution maps

Creating render pass contribution maps

In this scene (KitchenSinkModel.ma), there is a render layer, named KitchenSink, with two objects, a sink and a bowl, and a light. A Phong shader is applied to the sink and a Lambert shader is applied to the bowl.

1. Select the bowl and light in your scene view. In the Render Layer Editor, right-click the layer and select Pass Contribution Maps > Create Pass Contribution Map and Add Selected.

   passContributionMap1 is created. Double-click it and change its name to Bowl.

2. Select the sink and light in your scene view. In the Render Layer Editor, right-click the layer and select Pass Contribution Maps > Create Pass Contribution Map and Add Selected. Change its name to Sink.

Related topics

• Render Layer Editor window

Create render passes for each render pass contribution map

1. Open the Render Settings window and select mental ray as your renderer.
2. First, create the render passes for your sink render pass contribution map. Select the Passes tab and click the Create new render pass button to create new render passes. The Create Render Passes window appears.
3. Multi-select the following render passes: Diffuse Without Shadows, Reflection, Specular, and Shadow. In the Pass Prefix field, enter Sink. Click the Create and Close button. The following passes are created: SinkDiffuseNoShadow, SinkReflection, SinkShadow, SinkSpecular. The passes appear under the Scene Passes section.
   
4. Create the render pass for the bowl render pass contribution map. Select the Passes tab and click the button to create a new render pass. The Create Render Passes window appears. Select the Diffuse render pass and enter Bowl in the Pass Prefix field, then click Create and Close. The BowlDiffuse pass appears under the Scene Passes section.
5. Before you can apply these render passes to each pass contribution map, you must first make these passes available to the current layer. Use the button to move the passes to the Associated Passes section.
6. Using the Associated Pass Contribution Map drop-down list, select the pass contribution map that you want to select render passes for, for example, Sink.
7. Use the button to move the SinkDiffuseNoShadow, SinkReflection, SinkShadow, and SinkSpecular passes to the Passes Used by Contribution Map section.
8. Repeat this procedure to add the BowlDiffuse pass to the Passes Used by Contribution Map section for the Bowl pass contribution map.
9. Render the scene. Your rendered images are saved to the images directory of your project file as described below.

Related topics

• Passes tab
• Render pass nodes
• Multi-render passes

Creating subfolders and filenames for rendered images

By default, your rendered images are saved to the subdirectory <RenderLayer>\<camera>\<RenderPass> under the images\tmp directory of your project file. The image file name <scene>.iff is used for each rendered image.

Note:

All image output from render passes are saved to the images\tmp directory of your project file unless you run a batch render. Running a batch render saves your render passes output to the images directory.

Note:

If you render using the Render View window, you can also preview your render pass output by selecting File > Load Render Pass.

You may want to customize the subdirectories and filenames for the rendered images instead. For example, you may not want a folder to be created for each layer and camera. Use the tokens available from the File name prefix attribute under the File Output section in the Render Settings: Common tab. and combine them with separators such as _ or -.

For example, you may want to use the <Scene>_<RenderLayer>_<RenderPass> tags to create the filenames for your images. In this sample workflow, the following images are produced:

• KitchenSinkModel_KitchenSink_BowlDiffuse.iff
• KitchenSinkModel_KitchenSink_SinkDiffuseNoShadow.iff
• KitchenSinkModel_KitchenSink_SinkReflection.iff
• KitchenSinkModel_KitchenSink_SinkShadow.iff
• KitchenSinkModel_KitchenSink_SinkSpecular.iff
• KitchenSinkModel_KitchenSink_MasterBeauty.iff (This is the default beauty pass for the layer.)

Note:

If you use the default File Output directory, Maya creates a MasterBeauty folder to which it saves the default beauty pass for the layer. If you customize the File Output directory, a MasterBeauty.iff image is created for the beauty pass.

Using render pass sets in your scene

If your scene includes many render passes, you may want to group them into render pass sets. You can create render pass sets using the Create Render Passes window at the same time as when you are creating your render passes.

1. In the Create Render Passes window, select the passes that you want to include in your pass set.
2. Click the Create new render pass set button. In the renderPassSet Attribute Editor, enter a name for your render pass set, for example, Illumination.
3. The Illumination pass now appears in the Scene Passes section.
4. To render this pass set for the current layer, use the button to move the render pass set to the Associated Passes section.
   
5. Select the Illumination pass set and click the button. The Relationship Editor window appears and you can see that the Illumination pass is automatically associated with all the passes that you created simultaneously.
   
6. Render the scene. By default, the rendered images are saved to <RenderLayer>\<camera>\<RenderPass> under the images\tmp directory of your project file.

Related topics

• Relationship Editor