Class PolygonProceduralModel

Namespace

Stride.CommunityToolkit.Rendering.ProceduralModels

Assembly

Stride.CommunityToolkit.dll

Generates a planar polygon mesh (convex fan triangulation) from an arbitrary set of 2D vertices.

public class PolygonProceduralModel : PrimitiveProceduralModelBase, IProceduralModel

Inheritance

object

PrimitiveProceduralModelBase

PolygonProceduralModel

Implements

IProceduralModel

Inherited Members

PrimitiveProceduralModelBase.Scale

PrimitiveProceduralModelBase.SetMaterial(string, Material)

PrimitiveProceduralModelBase.Generate(IServiceRegistry)

PrimitiveProceduralModelBase.Generate(IServiceRegistry, Model)

PrimitiveProceduralModelBase.UvScale

PrimitiveProceduralModelBase.LocalOffset

PrimitiveProceduralModelBase.NumberOfTextureCoordinates

PrimitiveProceduralModelBase.MaterialInstance

PrimitiveProceduralModelBase.MaterialInstances

Remarks

Do not spawn these overlapping each other while they carry a physics collider. A polygon gets a convex-hull collider, and Bepu's hull-versus-hull contact generation returns depth = NaN for two overlapping extruded polygons. The NaN reaches the body poses on the same timestep, and Tree.Add then never returns - the application hangs with one core pegged and no exception to catch.

There is no safe Sides value to dodge it. A Monte Carlo sweep over random overlapping poses fails for every side count from 3 upwards, at 15-40% of placements once the bodies have rotated about Z; freshly spawned axis-aligned bodies fail at roughly 40% for 5, 7 and 8 sides. Triangles and custom-vertex polygons are exposed for the same reason. The identical placements with an analytic box collider never fail, so this is the hull path alone.

The only mitigation available today is to space spawns so hull-collider bodies do not start interpenetrating. A fix belongs upstream in Bepu; until it lands, treat overlap as unsupported.

Properties

Radius

Gets or sets the circumradius of the regular polygon used when Vertices is empty.

public float Radius { get; set; }

Property Value

float

Sides

Gets or sets the number of sides of the regular polygon used when Vertices is empty.

public int Sides { get; set; }

Property Value

int

Remarks

The value must be greater than or equal to 3. No value is safer than any other where physics is concerned - see the remarks on PolygonProceduralModel before spawning these overlapping.

Vertices

Gets or sets the vertex positions in the XY plane defining a custom polygon outline.

public Vector2[] Vertices { get; set; }

Property Value

Vector2[]

Remarks

When empty, a regular polygon is generated from Radius and Sides. Custom vertices must contain at least 3 unique points and should be ordered around a convex outline.

Methods

CreateMesh(Vector2[], float, float, bool)

Builds a new mesh for the given points (no caching). Assumes convex ordering; uses fan triangulation.

public static GeometricMeshData<VertexPositionNormalTexture> CreateMesh(Vector2[] points, float uScale = 1, float vScale = 1, bool toLeftHanded = false)

Parameters

points Vector2[]

The polygon vertices in the XY plane.

uScale float

The U coordinate scale factor.

vScale float

The V coordinate scale factor.

toLeftHanded bool

Whether to convert the mesh to left-handed coordinates.

Returns

GeometricMeshData<VertexPositionNormalTexture>

A geometric mesh data instance representing the polygon.

Exceptions

ArgumentNullException

Thrown when points is null.

ArgumentException

Thrown when points contains fewer than 3 points, duplicate points, or does not span both axes.

CreatePrimitiveMeshData()

protected override GeometricMeshData<VertexPositionNormalTexture> CreatePrimitiveMeshData()

Returns

GeometricMeshData<VertexPositionNormalTexture>

CreateRectangle(Vector2)

Convenience factory for an axis-aligned rectangle centered at the origin.

public static PolygonProceduralModel CreateRectangle(Vector2 size)

Parameters

size Vector2

The rectangle width and height.

Returns

PolygonProceduralModel

A polygon model configured with four rectangle vertices.

CreateTriangle(Vector2)

Convenience factory for an isosceles triangle centered at the origin.

public static PolygonProceduralModel CreateTriangle(Vector2 size)

Parameters

size Vector2

The triangle width and height.

Returns

PolygonProceduralModel

A polygon model configured with three triangle vertices.

GenerateRegularPolygonVertices(float, int)

Generates vertices for a regular polygon centered at the origin.

public static Vector2[] GenerateRegularPolygonVertices(float radius, int sides)

Parameters

radius float

The polygon circumradius. Must be greater than 0.

sides int

The number of polygon sides. Must be greater than or equal to 3.

Returns

Vector2[]

The generated polygon vertices in the XY plane.

Exceptions

ArgumentOutOfRangeException

Thrown when radius is not positive or sides is less than 3.

New(Vector2[], float, float, bool)

Creates (or retrieves from cache) a mesh for the supplied polygon vertex list.

public static GeometricMeshData<VertexPositionNormalTexture> New(Vector2[] vertices, float uScale = 1, float vScale = 1, bool toLeftHanded = false)

Parameters

vertices Vector2[]

The polygon vertices in the XY plane.

uScale float

The U coordinate scale factor.

vScale float

The V coordinate scale factor.

toLeftHanded bool

Whether to convert the mesh to left-handed coordinates.

Returns

GeometricMeshData<VertexPositionNormalTexture>

A geometric mesh data instance representing the polygon.

Exceptions

ArgumentNullException

Thrown when vertices is null.

ArgumentException

Thrown when vertices contains fewer than 3 points or duplicate points.