stride3d/stride · error · InvalidOperationException

Invalid GeometricPrimitive

Error message

Invalid GeometricPrimitive [{0}]. Expecting non-zero Vertices array

What it means

PrimitiveProceduralModelBase.Generate builds the mesh via CreatePrimitiveMeshData and requires at least one vertex. If the produced GeometricMeshData has an empty Vertices array the primitive type failed to produce geometry, so InvalidOperationException is thrown.

Solutions

Fix or initialize the primitive Type so CreatePrimitiveMeshData returns real geometry
Check custom CreatePrimitiveMeshData overrides to ensure they populate Vertices
Validate primitive parameters (slices, tessellation, scale) are non-degenerate before generating

Example fix

// before
public override GeometricMeshData<VertexPositionNormalTexture> CreatePrimitiveMeshData()
    => _cachedData; // may be empty
// after
public override GeometricMeshData<VertexPositionNormalTexture> CreatePrimitiveMeshData()
{
    var data = _cachedData ?? BuildSphere(tessellation);
    if (data.Vertices.Length == 0)
        data = BuildSphere(DefaultTessellation); // fall back to valid geometry
    return data;
}

Defensive patterns

Strategy: validation

Validate before calling

var data = primitive.CreatePrimitiveMeshData();
if (data == null || data.Vertices == null || data.Vertices.Length == 0)
    throw new InvalidOperationException("Primitive produced no vertices; check Type and parameters");

Try / catch

try { descriptor.Type.Generate(services, model); }
catch (InvalidOperationException ex) when (ex.Message.Contains("non-zero Vertices")) {
    logger.Error($"Primitive {descriptor.Type} generated an empty mesh");
}

Prevention

Validate primitive parameters (tessellation, radius, scale) before generating
Test custom IProceduralModel implementations with unit checks on vertex counts
Never return cached-but-uninitialized mesh data

When it happens

Trigger: A derived procedural model (Type property) whose CreatePrimitiveMeshData returns an empty vertex array — e.g. a primitive type not yet initialized, a custom primitive with zero parameters, or a type whose mesh generation silently produced nothing.

Common situations: ProceduralModelDescriptor with a custom IProceduralModel implementation returning empty data; uninitialized primitive Type field; degenerate parameters (e.g. zero tessellation) causing no vertices.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/bf1a5b1b0fdcb559. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Rendering/Rendering/ProceduralModels/PrimitiveProceduralModelBase.cs:103

        }

        public void Generate(IServiceRegistry services, Model model)
        {
            ArgumentNullException.ThrowIfNull(model);

            var needsTempDevice = false;
            var graphicsDevice = services?.GetSafeServiceAs<IGraphicsDeviceService>().GraphicsDevice;
            if (graphicsDevice == null)
            {
                graphicsDevice = GraphicsDevice.New();
                needsTempDevice = true;
            }

            var data = CreatePrimitiveMeshData();

            if (data.Vertices.Length == 0)
            {
                throw new InvalidOperationException("Invalid GeometricPrimitive [{0}]. Expecting non-zero Vertices array");
            }

            if (LocalOffset != Vector3.Zero)
            {
                for (var index = 0; index < data.Vertices.Length; index++)
                {
                    data.Vertices[index].Position += LocalOffset;
                }
            }

            //Scale if necessary
            if (Scale != Vector3.One)
            {
                var inverseMatrix = Matrix.Scaling(Scale);
                inverseMatrix.Invert();
                for (var index = 0; index < data.Vertices.Length; index++)
                {
                    data.Vertices[index].Position *= Scale;

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