Unity Bakery error fix

2025-11-05 10:54 UTC gpt-5-thinking Open in ChatGPT ↗

I am getting this error in Unity bakery. What’s the problem? Error exporting scene (Can’t fit Kitchen_Wall_A 1 0.001953125) - see console for details

here is the console print: Scene LOD levels: 0 UnityEngine.Debug:Log (object) ftBuildGraphics:DebugLogInfo (string) (at Assets/Editor/x64/Bakery/scripts/ftBuildGraphics.cs:390) ftBuildGraphics:MapObjectsToSceneLODs (ftBuildGraphics/ExportSceneData,UnityEngine.Object[]) (at Assets/Editor/x64/Bakery/scripts/ftBuildGraphics.cs:2954) ftBuildGraphics/d__265:MoveNext () (at Assets/Editor/x64/Bakery/scripts/ftBuildGraphics.cs:6750) ftRenderLightmap/d__342:MoveNext () (at Assets/Editor/x64/Bakery/scripts/ftRenderLightmap.cs:6394) ftRenderLightmap:RenderLightmapUpdate () (at Assets/Editor/x64/Bakery/scripts/ftRenderLightmap.cs:5597) UnityEditor.EditorApplication:Internal_CallUpdateFunctions ()

That message is coming from Bakery’s atlas packer while it’s exporting your scene for baking. It basically means: it couldn’t place the UV2 (lightmap) charts for that renderer (Kitchen_Wall_A) into any lightmap at the current settings. The tiny number at the end (0.001953125 = 1/512) is an internal size/scale value that hints the UVs/scale are degenerate or otherwise invalid.

The usual culprits (and quick fixes):

Bad or degenerate lightmap UVs on that mesh

In the FBX import settings for Kitchen_Wall_A: enable Generate Lightmap UVs (or re-unwrap UV2 in DCC), apply, reimport, then rebake.
If you authored UV2 yourself, check for overlaps, zero-area islands, NaNs, or UVs outside [0,1] and fix/repack.
Bakery’s docs call out incorrect lightmapping UVs as a common cause of export/rasterization failures. citeturn2view0

Object/renderer scale is near-zero or weird

In the scene, inspect the Transform scale for Kitchen_Wall_A and any parents. Avoid 0 or extreme scales; apply/freeze transforms in DCC and reimport.
In the Mesh Renderer > Scale In Lightmap, reset to 1 (or something sensible). A near-zero scale can make charts effectively unplaceable.

Packer/unwrapper settings

In Bakery window: set Atlas Packer = xatlas and enable Post-packing (this squeezes layouts better). citeturn2view0
If you rely on auto-unwrap: set Unwrapper = Default (or xatlas) and re-try; some unwraps that create overlapping/huge triangles can cause failures. citeturn2view0

Resolution too aggressive for the scene

Lower Texels Per Unit or the object’s Scale In Lightmap (to a reasonable, non-tiny value), or increase Max Resolution. Bakery’s manual explains how TPU and max size interact when packing. citeturn3search4

Isolate the problem mesh

Put Kitchen_Wall_A into its own Lightmap Group (User settings) so it gets its own atlas, or temporarily mark it Don’t Render in Bakery to confirm it’s the blocker. citeturn2view0

Why I think it’s UV-related in your case
That “Can’t fit … ” pattern often points to invalid/degenerate UV2 data (zero-area/NaN). There are reports where similar “Can’t fit … NaN NaN” errors were traced to NaN UVs on the offending object. If your model came from Blender/FBX, regenerating the UV map or re-exporting after cleaning the mesh usually fixes it. citeturn4search5turn4search3

If you want, paste a screenshot of Kitchen_Wall_A’s Model Import UV2 preview and its Mesh Renderer lightmapping section, and I’ll spot anything off and suggest exact values.

Got it — since it’s in a Bakery Lightmap Group, the “can’t fit” is usually caused by the group’s own constraints (fixed atlas size / texel density / preserve-UVs) making it impossible to pack that mesh. Here’s what to check, in order:

1) Prove it’s the group

Select Kitchen_Wall_A and temporarily remove the Bakery Lightmap Group Selector (or set Group = None) and rebake just that object.
- If it bakes: the group’s settings are too strict. Keep reading.
- If it still fails: it’s the mesh/UVs (degenerate UV2, bad scale, etc.).

2) If the group is the culprit, relax these settings

Open the Bakery Lightmap Group asset used by that wall and try:

Resolution
- If it’s fixed (e.g., 256/512), bump it up (1024 → 2048 → 4096).
- Or switch from a fixed resolution to automatic (if you’re using “Fit to scene bounds/auto” mode).
Texels Per Unit (TPU) / Density override
- If the group forces a high TPU, halve it (e.g., 100 → 50 → 25). High density + small atlas = un-packable.
Preserve/Use original UVs (names vary slightly by Bakery version)
- If enabled, try disabling it so Bakery can repack the charts. Preserving broken/oversized UV2 islands can make packing impossible.
Post-packing / xatlas
- Ensure the main Bakery window uses xatlas packer and Post packing is on. Groups still respect the global packer.
Scale in Lightmap overrides
- If the group forces a tiny multiplier, raise it toward 1.0. Extremely small values can generate micro-charts that fail rounding.

3) Split the group if it’s overloaded

If the group contains lots of big meshes (all walls, ceiling, etc.), the combined charts may not fit the group’s single atlas. Create multiple groups (e.g., Kitchen_Walls, Kitchen_Ceiling, Kitchen_Props) so each gets its own atlas.

4) Quick mesh sanity checks (still matter inside groups)

Transform scale of Kitchen_Wall_A and parents isn’t near-zero or extreme.
Model Import > Generate Lightmap UVs on the FBX (or clean UV2 in DCC).
Renderer > Scale In Lightmap not absurdly tiny.

A fast troubleshooting path

Remove from group → bake.
If it works, reassign to group and: increase group Resolution to 2048+, halve group TPU, disable Preserve UVs, and rebake.
If still failing, split the group so that Kitchen_Wall_A is alone (as a test). If that works, you just need more/larger atlases or lower density for the full set.

If you share a screenshot of the Group asset settings (Resolution/TPU/Preserve UVs) and the Model Import (UV2) panel for Kitchen_Wall_A, I’ll suggest exact values to use.