Modeling

Decimation

Decimation reduces a 3D mesh's polygon count by removing vertices and faces while preserving the overall shape as closely as possible.

Reduce Polygon Count

What is Decimation in 3D?

Decimation is a mesh simplification technique that reduces the number of polygons in a 3D model by collapsing edges and removing vertices, aiming to preserve the original shape within a specified error tolerance. It is the primary method for generating lower-detail versions of dense meshes for real-time use, web delivery, and LOD chains.

How it works

Decimation algorithms evaluate each edge or vertex by how much removing it would change the surface, then collapse the least-impactful elements first. The result approximates the original shape with fewer polygons but may lose fine detail and produce irregular topology unsuitable for animation. It differs from retopology, which rebuilds clean quad-based topology from scratch. Some file converters apply decimation automatically during format conversion, which can reduce quality unexpectedly. Decimation is available in Blender's Decimate modifier, ZBrush's Decimation Master, and Meshy's export pipeline.

Decimation vs remeshing

80-95% triangles

Typical scan reduction

Error tolerance in mm

Quality guard

Decimation

Remeshing

Operation

Collapses existing edges/vertices

Rebuilds the surface as a new mesh

Topology out

Irregular triangles

Uniform quads or tris with clean flow

Detail retention

Best silhouette per polygon

May soften sharp features

UVs & weights

Can be preserved

Regenerated, re-bake required

Reach for decimation when the asset must stay as-is but lighter; remesh when the topology itself is the problem.

In Meshy The free Polygon Reducer decimates GLB, FBX, OBJ and STL up to 100 MB locally in the browser, with a Keep UVs mode for textured assets.

Use cases

Reducing a high-poly scan or sculpt to a web-deliverable polygon count
Generating LOD meshes from a full-detail source model
Lowering file size for AR and mobile 3D experiences

Game Assets VR & AR 3D Printing

Last updated September 14, 2026

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Other terms

Retopology Low Poly Mesh Topology Draco Compression Albedo Map Bevel Bezier Curve Blend Shape

Frequently Asked Questions

Decimation reduces polygon count automatically by collapsing edges, preserving shape but producing irregular topology. Retopology rebuilds the mesh with clean, intentional edge flow suited for animation and subdivision. Decimation is faster; retopology gives better results for characters and deforming objects.

Decimation changes the mesh topology, which can distort UV layouts and cause texture stretching. For best results, rebake textures onto the decimated mesh or use a tool that handles UV reprojection automatically.

Some converters apply decimation by default to reduce file size during format conversion. This can lower quality unexpectedly. Check your converter's settings and disable automatic decimation if you need to preserve the original polygon count.

Add the Decimate modifier to the object and choose a mode: Collapse reduces by a ratio, Un-Subdivide removes subdivision levels, and Planar merges flat coplanar faces. Lower the ratio to reduce more polygons, then apply the modifier once you are satisfied with the shape retention.

Decimation reduces polygon count by collapsing existing edges, preserving the shape but leaving irregular triangle topology. Remeshing discards the original topology and rebuilds a clean, uniform mesh. Decimation is faster and keeps detail placement; remeshing produces tidier geometry better suited to animation.

It depends on the model, but dense scans and sculpts often decimate by 80 to 95 percent before the silhouette visibly degrades, especially if fine detail is preserved in a baked normal map. Watch the outline and prominent features as you reduce, since those reveal quality loss first.

A decimation ratio is the fraction of the original geometry retained. A ratio of 0.25 keeps roughly a quarter of the faces and removes three quarters. It gives predictable control over the final polygon count, which is why it is the most common decimation setting in modeling tools.

Decimation is ideal for one-off reduction of a static, high-detail mesh, such as preparing a scan for the web. Dedicated LOD tools generate a whole chain of progressively simpler versions with distance thresholds for real-time engines. Use decimation for a single target, LOD systems for automatic runtime switching.

Meshy's remesh and export pipeline includes decimation controls that let you target a specific polygon count or file size for web, AR, and game delivery. The reduced mesh retains its PBR texture set through an automatic rebake, so detail carries over even at low polygon counts.

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Decimation

What is Decimation in 3D?

How it works

Decimation vs remeshing

Use cases