How To Avoid Ngons

Avoiding ngons (non-planar or non-quadrilateral polygons, typically polygons with more than 4 sides) is important in 3D modeling for clean topology, better deformations, and predictable rendering. Here’s how to avoid them, depending on your workflow and software:

🧩 What Are Ngons?

Ngons are polygons with more than 4 sides (e.g., pentagons, hexagons, etc.). Most game engines and rendering pipelines prefer quads (4 sides) or tris (3 sides) for consistency and performance.

✅ How to Avoid Ngons

1. Model with Quads and Tris

Always aim to build your mesh using quads as the base.
Use tris only where necessary (tight corners, caps, etc.).
Avoid tools that auto-create flat surfaces with many edges (like the “Fill” tool) unless you plan to retopologize.

2. Use the Knife or Connect Tools

When you see a face with 5+ edges, use the knife, cut, or connect tool to divide it into quads and tris.
In Blender: use K (Knife Tool), J (Join Vertices), or Ctrl+R (Loop Cut).

3. Check for Ngons

Use built-in features in your 3D software to highlight ngons:

Blender:

Edit Mode → Select → Select Faces by Sides → Greater than 4
Or enable Mesh Analysis in overlays for visual feedback

Maya:

Use the Cleanup Tool (Mesh → Cleanup) and check Ngons

3ds Max:

Use the Graphite Modeling Tools → Polygon Modeling → Quadrify All

4. Avoid Booleans Without Cleanup

Boolean operations (union, subtract, intersect) often generate ngons.
Always retopologize or manually clean up after using booleans.

5. Use Proper Retopology

If you sculpt or generate complex forms (e.g., from ZBrush), use retopology tools to rebuild with clean quads.

🧼 Tips for Clean Topology

Follow edge loops for better deformation in animations.
Use grid flow in flat areas.
Cap holes or cylinders using tri fans or a quad grid rather than a big ngon.

🔁 When Are Ngons OK?

For non-deforming meshes (e.g., still props, background objects), ngons are less harmful.
In high-poly models used only for baking normal maps or concept sculpts, ngons are acceptable.