# ChainSegmentGeometry > The geometry of a chain line segment with one-sided collision which only collides on the "right" side. Several of these are generated for a chain, connected as ghost1 -\> point1 -\> point2 -\> ghost2. ## Definition * **Type:** Struct * **Namespace:** [Unity.U2D.Physics](/engine/6000.7/script-reference/unity/u2d/physics.md) * **Assembly:** UnityEngine.PhysicsCore2DModule * **Implements:** [IEquatable\](https://learn.microsoft.com/dotnet/api/system.iequatable-1) ```csharp public struct ChainSegmentGeometry : IEquatable ``` ## Static Fields | Value | Description | | ------------------------------------------------------------------------------------------------------------ | ------------------------------ | | [defaultGeometry](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/defaultgeometry.md) | Get the default Chain Segment. | ## Constructors | Constructor | Description | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | | [ChainSegmentGeometry()](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/ctor.md#chainsegmentgeometry\(\)) | Create a default ChainSegment. See [\_defaultGeometry](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/defaultgeometry.md). | | [ChainSegmentGeometry(Unity.U2D.Physics.SegmentGeometry,UnityEngine.Vector2,UnityEngine.Vector2)](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/ctor.md#chainsegmentgeometry\(segmentgeometry-vector2-vector2\)) | Create a default ChainSegment. | ## Properties | Property | Description | | -------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [areEdgesValid](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/areedgesvalid.md) | Whether the two points defining [\_segment](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/segment.md) are far enough apart to form a valid edge. | | [ghost1](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/ghost1.md) | The tail ghost vertex. A ghost vertex is used by the solver to define how a collision response should be handled when a contact with the vertex occurs. | | [ghost2](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/ghost2.md) | The head ghost vertex A ghost vertex is used by the solver to define how a collision response should be handled when a contact with the vertex occurs. | | [isValid](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/isvalid.md) | Whether the geometry describes a chain segment that can be used. | | [segment](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/segment.md) | The Segment. | ## Methods | Method | Description | | -------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [CalculateAABB](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/calculateaabb.md) | Calculate the AABB of the geometry. | | [CastRay](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/castray.md) | Calculate if a world ray intersects the geometry. See [PhysicsQuery.CastResult](/engine/6000.7/script-reference/unity/u2d/physics/physicsquery/castresult.md). | | [CastShape](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/castshape.md) | Calculate if a cast shape intersects the geometry. Initially touching shapes are treated as a miss. You should check for overlap first if initial overlap is required. See [PhysicsQuery.CastShapeInput](/engine/6000.7/script-reference/unity/u2d/physics/physicsquery/castshapeinput.md) and [PhysicsQuery.CastResult](/engine/6000.7/script-reference/unity/u2d/physics/physicsquery/castresult.md). | | [ClosestPoint](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/closestpoint.md) | Calculate the closest point on this geometry to the specified point. | | [CreateShapeProxy](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/createshapeproxy.md) | Create a shape proxy from the geometry. | | [InverseTransform](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/inversetransform.md) | Inverse-Transform the geometry. | | [Transform](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/transform.md) | Transform the geometry. | ## Static Methods | Method | Description | | -------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [CreateSegments](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/createsegments.md) | Create multiple [ChainSegmentGeometry](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry.md) from a set of vertices. The rules for interpreting the specified vertices when creating segments is described in [PhysicsChain](/engine/6000.7/script-reference/unity/u2d/physics/physicschain.md). | | [InverseTransform](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/inversetransform.md) | Inverse-Transform a batch of geometry in place. | | [Transform](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/transform.md) | Transform a batch of geometry in place. | | [UpdateSegments](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/updatesegments.md) | Update an existing batch of [ChainSegmentGeometry](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry.md) from a set of vertices, writing the results into the specified span in place. This pairs with [ChainSegmentGeometry.CreateSegments](/engine/6000.7/script-reference/unity/u2d/physics/chainsegmentgeometry/createsegments.md): it recalculates the same segment and ghost vertices, but reuses a caller-provided span rather than allocating a new one. The span length must equal the segment count the vertices produce, which is the vertex count when `isLoop` is true, otherwise the vertex count minus three. |