How do you use render layers and passes to speed up your baking and caching workflow?

1 What are render layers and passes?

Render layers and passes are ways of splitting your scene into smaller and simpler parts for rendering. A render layer is a collection of objects and materials that share the same render settings, such as camera, lights, shadows, and visibility. A render pass is a subset of a render layer that isolates a specific attribute or effect, such as color, depth, normal, ambient occlusion, or reflection. By using render layers and passes, you can control which parts of your scene are baked and cached, and how they are combined and composited in the final image.

2 How to create and use render layers?

To create a render layer, you need to select the objects and materials that you want to include in the layer, and assign them to a new or existing layer. You can also use collections, groups, or tags to organize your scene into logical categories, such as foreground, background, characters, props, etc. You can then enable or disable the visibility and renderability of each layer, as well as adjust the layer-specific settings, such as camera, lights, shadows, and effects. To use a render layer for baking and caching, you need to enable the bake or cache option for the layer, and specify the output format, resolution, and location of the baked or cached file. You can also choose which render passes to include in the bake or cache, such as diffuse, specular, emission, etc.

3 How to create and use render passes?

To create a render pass, you need to enable the pass type that you want to isolate in the render settings of the layer. For example, if you want to isolate the reflection pass, you need to enable the reflection pass in the render settings of the layer that contains the reflective objects and materials. You can also create custom passes by using nodes, shaders, or scripts to define the attributes or effects that you want to isolate. To use a render pass for baking and caching, you need to enable the bake or cache option for the pass, and specify the output format, resolution, and location of the baked or cached file. You can also choose which render layers to include in the bake or cache, such as the layer that contains the reflection pass, or the layer that contains the object that reflects.

4 How to combine and composite render layers and passes?

To combine and composite render layers and passes, you need to use a compositing software or tool that can read and manipulate the baked or cached files. For example, you can use Blender's compositor, Photoshop's layers, or After Effects' compositions to combine and composite render layers and passes. You can also use nodes, filters, masks, or effects to adjust the color, contrast, opacity, blending mode, or other parameters of each layer or pass. By combining and compositing render layers and passes, you can create complex and realistic images with less rendering time and resources.

5 How to save and manage your baked and cached files?

To save and manage your baked and cached files, you need to use a naming convention and a folder structure that can help you identify and organize your files. For example, you can use the name of the render layer or pass, the name of the object or material, the resolution, the format, or the date as part of the file name. You can also use subfolders to group your files by scene, layer, pass, or attribute. You can also use a file browser or a project manager to view and access your files, as well as delete or backup your files when needed. By saving and managing your baked and cached files, you can avoid confusion, duplication, or loss of data.