Last reviewed 31 Jul 2026

Applies to

Blender 4.5 LTS Maya 2026 Unity 2022.3 LOD workflows

Difficulty Intermediate

Reduce Meshes in Blender or Maya for Unity LODs

A Unity LOD setup needs separate meshes with progressively less geometry. Blender's Decimate modifier and Maya's Reduce command can produce those meshes while leaving the detailed source available for further editing.

Create one lower-detail mesh

Duplicate the detailed model, reduce the duplicate, and judge the result from the distance where Unity will display it.

Keep the detailed mesh as AssetName_LOD0.
Create and inspect AssetName_LOD1 in Blender or Maya.
Export the grouped LOD meshes to FBX and verify Unity's generated LOD Group.

VRChat note

Mesh reduction changes only the source asset. Test the completed LOD Group inside the world from normal player viewpoints and on every platform the world supports.

Prepare the Source Mesh

Work from a duplicate so the detailed model remains recoverable.

Save a new version of the Blender or Maya file.
Duplicate the original object.
Keep transforms, pivot placement, materials, and object scale consistent between copies.
Name the detailed object AssetName_LOD0.
Name the first reduced copy AssetName_LOD1.

Unity documents LOD0 as the most detailed level. Increasing numbers identify progressively lower-detail versions.

Before reducing anything, record the source triangle count and inspect:

The outer silhouette.
Open mesh borders.
UV seams and material boundaries.
Hard or sharp edges.
Thin parts that could collapse.
Areas that deform if the model is animated.

These checks provide a reference when the reduced mesh changes shading or loses an important feature.

Reduce a Mesh in Blender

Blender's Decimate modifier reduces vertex and face counts with three modes.

Mode	Use it for	Important control
Collapse	General mesh reduction	Ratio controls the proportion of faces retained.
Un-Subdivide	Grid-like topology created by subdivision	Iterations removes subdivision steps; edited topology can produce unexpected results.
Planar	Models dominated by flat surfaces	Angle Limit and delimit options control which edges can dissolve.

Collapse workflow

Select the AssetName_LOD1 object.
Open Modifier Properties.
Choose Add Modifier > Generate > Decimate.
Leave the mode set to Collapse.
Lower Ratio gradually while watching the silhouette and face count.
Enable Symmetry when the model needs reduction across one matching axis.
Use a Vertex Group when an important region needs different reduction influence.
Inspect the result in Object Mode from several angles.
Apply the modifier only when the result is ready for export.

Blender defines a Ratio of 1.0 as unchanged and 0.5 as retaining approximately half the faces used by the calculation. Because Blender calculates the ratio with triangles, the displayed face result can differ when quads or other polygons remain and Triangulate is disabled.

Planar workflow

For architecture and other mostly flat models:

Change the Decimate mode to Planar.
Increase Angle Limit cautiously.
Use Delimit options to protect relevant Normal, Material, Seam, Sharp, or UV boundaries.
Inspect corners, openings, material borders, and UV seams before applying the modifier.

Planar mode is designed to dissolve detail on mainly flat forms. It is not a replacement for Collapse mode on every asset.

Reduce a Mesh in Maya

Maya's Reduce feature creates a polyReduce node, so its settings remain adjustable in the construction history.

Switch to the Modeling menu set.
Select the mesh or the faces to reduce.
Choose Mesh > Reduce and open its options.
Enable Keep original when you want Maya to retain a comparison copy.
Choose a reduction method:
- Percentage
- Vertex limit
- Triangle limit
Configure the needed Feature Preservation options.
Run Reduce.
Adjust the polyReduce node while comparing the result with the original.

Maya attempts to meet the chosen target, but preservation options can prevent the result from matching an exact vertex or triangle limit.

Useful preservation controls include:

Control	What it protects
Mesh borders	The shape of open polygon boundaries.
UV borders	UV island boundaries; dense UV borders can limit reduction or produce unexpected results.
Symmetry	Corresponding reduction across the selected symmetry plane.
Keep original	A retained source mesh for comparison and painted reduction weights.

For local control, Maya's Paint Reduce Weights Tool changes how strongly different areas are reduced. Autodesk documents darker painted regions as receiving more reduction and lighter regions as being preserved more strongly.

Inspect Each Reduced Mesh

Do not approve a lower LOD from polygon count alone. Check:

Silhouette from the intended viewing distance.
Shading under representative scene lighting.
UVs and texture placement.
Material assignments.
Open borders and holes.
Thin geometry and disconnected pieces.
Pivot, origin, position, rotation, and scale.

Compare the model at the point where Unity will switch to it. A defect that is obvious in a close-up may be invisible at the intended transition, while a damaged silhouette can remain noticeable from far away.

Create another duplicate for AssetName_LOD2 only when the asset needs an additional level. Reduce the previous lower-detail mesh or the original according to which approach preserves the required form more reliably.

Name and Export the LOD Set

Unity 2022.3 recognizes grouped meshes that use this naming pattern:

AssetName_LOD0
AssetName_LOD1
AssetName_LOD2

The suffix must use _LOD followed by the level number. LOD0 is the most detailed mesh.

Group the related LOD objects.
Confirm their transforms and pivots align.
Export the group as one FBX file.
Import the FBX into the Unity project.
Open the imported model and confirm Unity created an LOD Group.

Unity's import documentation says correctly grouped and named meshes can automatically create and configure the LOD Group. If the automatic setup is not suitable, the renderers can also be assigned to an LOD Group manually.

Verify the LOD Group in Unity

Select the imported asset and inspect the LOD Group:

Confirm LOD0 uses the detailed renderer.
Confirm each following level uses the matching lower-detail renderer.
Drag the camera icon across the LOD selection bar to preview transitions.
Check the transition percentages from realistic scene viewpoints.
Use Recalculate Bounds after changing the renderers or LOD levels.
Enter Play Mode and approach the object from several directions.

Unity calculates LOD thresholds from the object's screen-space height rather than from a fixed world-distance value. Camera framing and object scale therefore affect when a transition occurs.

Troubleshooting

The reduced mesh has holes or damaged borders.

Undo the reduction and preserve boundary features more strongly. In Blender Planar mode, review the Delimit settings. In Maya, increase Mesh borders preservation before reducing again.

UV seams or material edges moved.

Protect the relevant UV, seam, or material boundaries and use a less aggressive target. Recheck the texture on the reduced mesh before export.

Blender's Ratio does not match the face count I expected.

Blender calculates Collapse Ratio with triangles. Quads and other polygons can make the remaining face count differ from the simple percentage shown by the Ratio value.

Maya does not reach the exact triangle target.

Feature Preservation options can keep Maya from reaching the precise target. Review which boundaries must be retained, then adjust the target or preservation settings.

Unity did not create an LOD Group after import.

Confirm the meshes are grouped in one export and named with matching base names followed by _LOD0, _LOD1, and subsequent level numbers. Reimport the FBX after correcting the hierarchy and names.

The LOD switch visibly pops.

Compare the silhouettes of the two active levels, reduce the geometry difference, or move the transition to a smaller screen-space size. Preview the transition with the LOD Group selection bar and retest in Play Mode.