Blender Cycles Texture Baking Guide: UVs, Targets and Margins

Blender’s current manual covers baking material and lighting information into image textures with Cycles for purposes such as transferring textures to game engines, working with procedural textures and creating lightmaps. Before starting, you need to prepare a UV map for the mesh object and a target for the baked data. The manual does not specify a particular Blender version; the steps below are based on features described in the current Blender Manual’s Cycles baking and UV documentation.

1. Prepare the mesh and UV map

1. Select the mesh object to bake. If it has no UV map, go to the Data tab in the Properties editor, then open the UV Maps panel. You can create a new UV map or select an existing one from the panel.

2. View and check the UV map in the UV Editor. Baking transfers surface information to the target image based on these coordinates, so the UV layout intended for the target must be ready.

3. If the object has multiple UV maps, mark the map to be used for rendering as Active Render. According to Blender’s manual, this selection determines the UV map used for the UV Pass and some UV coordinate usage in material shading.

A single UV map can be used for multiple textures, and you can also create multiple UV maps on the same mesh when needed. Deciding which map to use before baking helps ensure that the coordinates match the texture target.

2. Choose the bake target and type

1. Create an Image Texture node in the material for the bake result, and make it active and selected. Alternatively, you can use a Color Attribute on the mesh. According to the manual, the target is the active Image Texture node or active Color Attribute.

2. Choose a bake type from the Render › Bake panel. For example, Ambient Occlusion bakes AO information specified in the World settings without taking scene lights into account; Normal transfers surface normals to an RGB image. Diffuse, Glossy, Roughness, Emit and Transmission extract their corresponding material passes. Combined combines materials, textures and lighting, excluding specularity.

3. Review the relevant contributions if you need to limit the effect of the selected type. For Combined and some other bake types, you can choose direct or indirect lighting, as well as Diffuse, Glossy, Transmission and Emit contributions. The Color option determines whether the pass is captured as a color or grayscale contribution.

Baking uses the current render settings, including sampling and bounce values. As a result, according to the manual, the quality of baked textures can match the scene render. Baking AO for main objects in advance can save render time by reducing the need to enable AO for the entire scene during the final render.

3. Bake from selected objects to the active object

1. To transfer surface information from a high-resolution model to a low-resolution active object, use Selected to Active. Rays are cast from the low-poly object toward the high-poly object.

2. Adjust the ray distance if the transfer shows projection errors or missing information. Max Ray Distance sets how far inward the rays can reach when Cage is not used. Extrusion is one of the settings associated with the Cage option. For more control, you can use a Cage Object.

3. If the existing base mesh does not produce a good Cage, you can edit a copy of the base mesh and use it as the Cage. The two meshes must have the same topology in terms of face count and face order. The manual also notes that high-poly objects can be joined before baking to reduce memory issues caused by the process.

This method is useful when you need to use the surface information of a detailed model as a texture on a simpler mesh. However, Cage and ray distance settings do not produce the same results for every model, so it is important to check the output image and adjust as needed.

4. Margins and architectural visualization workflows

1. Check the Margin setting when baking to an image. By default, Blender creates a margin around UV islands. This area helps prevent seams at UV boundaries when texture filtering and mipmapping are used. Extend expands the edge pixels outward, while Adjacent Faces fills the margin with pixels from faces adjacent across UV seams. The size is set in pixels; because the manual does not recommend a fixed value, do not assume a specific number for every scene.

For architecture and interior visualization teams, baking can be useful for transferring material information to image textures or preparing intensive lighting and shadow information, such as AO, in advance. If the goal is to transfer assets to a game engine or create a lightmap, check the bake type, active UV map and target texture together. The manual does not specify particular hardware, licensing or version compatibility requirements; as a first check, confirm that the relevant Cycles panel and target node are available in your Blender installation.

Common mistakes

• Starting a bake without creating a UV map for the mesh.

• Expecting an image bake to work without an active and selected Image Texture target in the material. In this case, the bake will not run for that material.

• Forgetting to check which UV map is active for rendering when multiple maps are present.

• Ignoring the margin around UV islands, which can make seams visible during filtering.

• Failing to match the topology of Cage meshes during Selected to Active baking, or overlooking ray distance issues.