Render Baking

Cycles shaders and lighting can be baked to image textures. This has a few different purposes, most commonly:

  • Baking textures like base color or normal maps for export to game engines.

  • Baking ambient occlusion or procedural textures, as a base for texture painting or further edits.

  • Creating light maps to provide global illumination or speed up rendering in games.

Note

Baking is not supported on OptiX GPU rendering.

Setup

Baking requires a mesh to have a UV map, and either vertex colors or an Image Texture node with an image to be baked to. The Active Image Texture node or Vertex Color layer is used as the baking target.

Use Render Bake in intensive light/shadow solutions, such as AO or soft shadows from area lights. If you bake AO for the main objects, you will not have to enable it for the full render, saving render time. Cycles uses the render settings (samples, bounces, …) for baking. This way the quality of the baked textures should match the result you get from the rendered scene.

Settings

Reference

Panel

Render ‣ Bake

Bake

Perform the baking operation.

Bake from Multires

Bake directly from multires object.

Bake Type

Type of pass to bake.

Combined

Bakes all materials, textures, and lighting except specularity. The passes that contribute to the combined pass can be toggled individually to form the final map.

Ambient Occlusion

Bakes ambient occlusion as specified in the World panels. Ignores all lights in the scene.

Shadow

Bakes shadows and lighting.

Normal

Bakes normals to an RGB image.

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.

Roughness

Bakes the roughness pass of a material.

Emit

Bakes Emission, or the Glow color of a material.

Environment

Bakes the environment (i.e. the world surface shader defined for the scene) onto the selected object(s) as seen by rays cast from the world origin.

Diffuse

Bakes the diffuse pass of a material.

Glossy

Bakes the glossiness pass of a material.

Transmission

Bakes the transmission pass of a material.

Influence

Combined

Lighting
Direct

Add direct lighting contribution.

Indirect

Add indirect lighting contribution.

Contributions
Diffuse

Add diffuse contribution.

Glossy

Add glossy contribution.

Transmission

Add transmission contribution.

Ambient Occlusion

Add ambient occlusion contribution.

Emit

Add emission contribution.

Diffuse, Glossy, Transmission

Contributions
Direct

See above.

Indirect

See above.

Color

Colorize the pass.

  • If only Color is selected you get the pass color, which is a property of the surface and independent of sampling refinement.

  • If Color is not selected, you get the direct and/or indirect contributions in gray-scale.

  • If Color and either Direct or Indirect are selected, you get the direct and/or indirect contributions colored.

Normal

Space

Normals can be baked in different spaces:

For materials, the same spaces can be chosen in the image texture options next to the existing Normal Map setting. For correct results, the setting here should match the setting used for baking.

Object

Normals in object coordinates, independent of object transformation, but dependent on deformation.

Tangent

Normals in tangent space coordinates, independent of object transformation and deformation. This is the default, and the right choice in most cases, since then the normal map can be used for animated objects too.

Swizzle R, G, B

Axis to bake into the red, green and blue channel.

Selected to Active

Bake shading on the surface of selected objects to the active object. The rays are cast from the low-poly object inwards towards the high-poly object. If the high-poly object is not entirely involved by the low-poly object, you can tweak the rays start point with Max Ray Distance or Extrusion (depending on whether or not you are using cage). For even more control you can use a Cage Object.

Note

There is a CPU fixed memory footprint for every object used to bake from. In order to avoid crashes due to lack of memory, the high-poly objects can be joined before the baking process. The render tiles parameter also influence the memory usage, so the bigger the tile the less overhead you have, but the more memory it will take during baking (either in GPU or CPU).

Cage

Cast rays to active object from a cage. A cage is a ballooned-out version of the low-poly mesh created either automatically (by adjusting the ray distance) or manually (by specifying an object to use). When not using a cage the rays will conform to the mesh normals. This produces glitches on the edges, but it is a preferable method when baking into planes to avoid the need of adding extra loops around the edges.

Cage Object

Object to use as cage instead of calculating the cage from the active object with the Cage Extrusion.

Cage Extrusion

Distance to use for the inward ray cast when using Selected to Active and Cage. The inward rays are casted from a version of the active object with disabled Edge Split Modifiers. Hard splits (e.g. when the Edge Split Modifier is applied) should be avoided because they will lead to non-smooth normals around the edges.

Note

When the base mesh extruded does not give good results, you can create a copy of the base mesh and modify it to use as a Cage. Both meshes need to have the same Topology (number of faces and face order).

Max Ray Distance

Distance to use for the inward ray cast when using Selected to Active. Ray distance is only available when not using Cage.

Output

Target

Where to output the baked map.

Image Textures

Bake to the image data-block associated with the Active Image Texture node.

Margin

Baked result is extended this many pixels beyond the border of each UV “island”, to soften seams in the texture.

Clear Image

If selected, clears the image before baking render.

Vertex Colors

Bake to the Active Vertex Color layer on the active mesh. Note, the active object must be a mesh as other object types do not have vertex colors.