G2 continuity

Also called curvature continuity, g3 continuity, class-a

Two curves or surfaces meet G2 when they share position, tangent, and curvature at the join — the curvature comb crosses it without a step. Reflections then flow unbroken across the transition, which is the entire point. G3 additionally matches the rate of curvature change, and is what bodywork demands where a highlight must not visibly accelerate.

Two curves joined with matching tangent and curvature, their combined curvature comb passing across the join as one continuous envelope with no step.

In practice

'Curvature continuous.' The difference from G1 is invisible in wireframe and unmistakable in chrome — which is why surfacing reviews happen under strip lights and not in the viewport.

Not to be confused with

G1 continuityTwo curves or surfaces meet G1 when they share a point and a tangent direction there, but not necessarily curvature. The join reads as smooth in outline and in a matte render, and shows a hard kink under a specular highlight or a zebra stripe, because the reflected direction jumps. G0 below it is contact only: position, no shared tangent.

How this term connects

Related Confused with

In practice

Not to be confused with

Related

How this term connects

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