In short: prepare a detailed high-poly source and a clean low-poly destination, unwrap the low-poly mesh, create a bake cage and transfer the required surface information into image maps. Inspect the bake for seams and missing rays, then test the imported material in the engine. Baking replaces geometry detail with texture data; it does not replace proper topology, UVs or art direction.
The workflow is most useful when the high-poly sculpt carries detail the game can see but should not simulate. That may be engraved metal, stitched fabric, surface grain or tiny panel work. The low-poly version carries the silhouette, deformation and runtime budget. The baked maps connect the two.
What is texture baking in Blender?
Texture baking renders information into an image attached to the active UV map. The source may be the same mesh’s material, another selected high-poly mesh, lighting, ambient occlusion or a specific shader pass. The result becomes a texture the destination renderer can sample without rebuilding the original node graph or geometry.
Blender’s Cycles baking documentation describes the bake types and selection rules. For games, normal, base colour, ambient occlusion and roughness are common. Metallic, height or curvature maps are useful only when the target shader reads them.
| Bake job | Input | Output |
|---|---|---|
| High-to-low normal | Selected high detail to active low-poly surface | Tangent-space normal map |
| Procedural material transfer | Shader graph on the active mesh | Image maps for the destination material |
| Ambient occlusion | Surface geometry and ray visibility | Occlusion map for shader or baked lighting use |
| Material masks | Procedural selection, wear or ID data | Roughness, metallic or custom mask textures |
When should you bake high-poly detail to a low-poly asset?
Bake when visual detail matters but geometry cost should stay within a game or real-time budget. The classic case is a detailed prop or character where the high-poly version establishes shape, wear and engraved detail, while the low-poly version supplies a manageable UV, deformation and LOD surface.
Do not bake high-poly detail onto a low-poly mesh whose silhouette is wrong. A normal map changes shading, not outline. Rebuild the base shape or retopologize first when the large form, deformation or hard-surface bevels are incorrect.
- Good bake: visually dense surface, stable silhouette, controlled runtime mesh.
- Bad bake: missing UV margin, mismatched surfaces, stretched topology or wrong tangent basis.
- Not a bake: correcting the shape or topology inside a painted texture.
How do you prepare the high-poly, low-poly and UVs?
Freeze the high-poly silhouette and material story before the low-poly pass. Retopologize the destination mesh, apply transforms and create a deliberate UV layout. Bake from a clean relationship between the two surfaces, not from objects with different scale, rotation or hidden parts.
The low-poly UVs decide where the bake can put detail. Keep seams away from the most visible surface where possible, give islands enough space for bleed and confirm that matching edges use compatible smoothing and normals. The UV unwrapping guide covers island scale, seam placement and checker-map inspection.
| Stage | Required state | Failure if skipped |
|---|---|---|
| High-poly | Final detail, material and silhouette | Baked art is revised after the maps exist |
| Low-poly | Final topology, deformation and applied scale | Bake must be repeated after retopology |
| UVs | Packed islands, consistent density and enough margin | Stretching, seams and missing edge detail |
| Normals | Matching smoothing at UV boundaries | Visible lighting breaks at seams |
| Cage | Enough coverage without hitting the wrong surface | Missing detail, holes or ray intersections |
Which maps should you bake for a game asset?
Bake the maps your final material actually samples. A normal map is usually essential for high-to-low detail. Base colour and roughness support the shader. Ambient occlusion can add surface depth, but over-baked AO can double-darken a scene once engine lighting is applied.
| Map | Purpose | Color-space default |
|---|---|---|
| Normal | Surface direction and fine detail | Non-Color data |
| Base colour | Albedo or stylised surface colour | sRGB colour |
| Roughness | Microsurface response | Non-Color data |
| Metallic | Conductor versus dielectric response | Non-Color data |
| AO | Local occlusion information | Non-Color data |
Use the correct channel packing of the target engine. Do not assume one engine’s packed roughness/metallic/AO texture is accepted by another without remapping.
How do you fix seams, blank images and missing rays?
Start with the bake target. Confirm that the intended low-poly object is active, the high-poly object is selected, the correct UV map is active and the material has an image node selected. Blank images often come from one of those simple selection errors.
If only edges are missing, adjust island margin, cage extrusion and ray distance before increasing resolution. If detail is noisy, check whether the cage intersects other geometry or the low-poly surface has bad normals. The source may also be too dense or too far away from the target.
| Problem | Likely cause | Correction |
|---|---|---|
| Entire texture is blank | No active image or wrong bake target | Select the target and image node explicitly |
| White or missing UV islands | UV margin too small or no rays hit | Add margin, adjust cage and ray distance |
| Visible seam lighting | Edge normals or tangent frame mismatch | Fix smoothing, UV orientation and seam placement |
| Surface detail is inverted | Normal direction or height source is reversed | Check tangent convention and green channel |
| Edges look blurry | Resolution too low or uneven texel density | Increase relevant resolution or repack UVs |
How do you bake procedural materials into textures?
Use the shader graph to establish the material, then bake the visible contribution into the image channels the engine understands. Keep procedural sources and the baked images together until the material is accepted. The images are a delivery format, not the editable source.
For a normal map specifically, inspect the final tangent-space result and follow the Blender normal-map direction and validation workflow. For the material direction itself, use the Blender AI texture generator guideto keep UV scale, roughness and normal information consistent.
- Bake base colour separately from data maps.
- Keep roughness and metallic as Non-Color channels.
- Pack maps only after the destination shader is known.
- Save final images with descriptive names and stable resolutions.
- Retain the source .blend and original procedural material.
How do you validate baked textures in Unity or Unreal?
Import the maps into the target engine and use its texture types and compression settings. Connect the normal map through the correct slot, set roughness/metallic channels as data and test the asset under gameplay lighting. The engine import is the acceptance environment.
Follow the Unity texture import and material guidance for texture type, sRGB and compression. For Unreal, inspect normal-map import and material node settings before evaluating the final look. Test both close-up and gameplay distance, because fine baked detail that looks good in a turntable can become noise at runtime.
- Inspect normal direction under one dominant light.
- Check AO and roughness for doubled or flattened shading.
- Verify seam visibility at the intended camera distance.
- Check mipmaps, compression artifacts and texture memory.
- Compare the low-poly LOD against the high-poly reference.
When should you rebake, retopologize or reuse the source?
Rebake when the high-poly surface, low-poly topology, UVs, cage, normals or material graph changed. Retopologize before baking when the low-poly mesh cannot support the intended silhouette, deformation or UV layout. Reuse the existing bake when only a small paint correction is needed and the data underneath remains valid.
Keep a record of high-poly and low-poly versions. A baked texture is linked to the exact surfaces and UV layout that produced it. If someone edits the low-poly shape later, the map may still look plausible while silently carrying detail from an obsolete surface.
Key takeaways
- Baking transfers surface information into textures; it does not fix silhouette, topology or UV design.
- Prepare the final high-poly, final low-poly and UV layout before creating the bake cage.
- Bake only the maps the runtime material consumes and use the correct color space for each.
- Diagnose blank maps and seams through selection, UV margin, normals, cage and ray distance before changing resolution.
- Accept the bake in Unity or Unreal under real lighting and at real gameplay distance.