Pole
Vertex where edge-count breaks
Also known as: N-pole · E-pole · 5-pole · 3-pole
Definition
A pole is a vertex where the number of incident edges differs from the regular grid count of 4. An E-pole (or 5-pole) has 5 edges; an N-pole has 3. Poles are necessary anywhere edge-flow needs to bend, branch, or terminate — but they cause shading artefacts under subdivision and can pinch under skinning. Placing poles is craft: hide them in flat areas, never in highly-curved or deforming geometry.
In production
Standard advice: keep poles off the silhouette and away from deforming joints. A pole on the back of a character's thigh is fine; a pole on the front of an elbow will visibly crease on every bend, because subdivision surfaces (Catmull-Clark, used by Maya, Blender, and 3ds Max) shade poles with a visible pinch or flat spot compared to the surrounding regular grid. ZBrush's ZRemesher and Maya's Quad Draw both try to minimize pole count automatically, but automatic retopology frequently places poles directly on facial landmarks like the corner of the mouth, requiring manual cleanup for hero characters. A 3-pole (N-pole, only 3 edges) is generally worse than a 5-pole (E-pole) under subdivision since it creates a sharper pinch, so experienced modelers will deliberately convert problem N-poles into a pair of E-poles during retopology. Poles also affect UV unwrapping — placing a seam through a pole often produces a UV shell with a stretched, fan-shaped corner that's hard to texture cleanly.
