What causes "The vertex stride is not a multiple of 4 bytes" in stride3d/stride?

Add a padding element (e.g. an R8G8B8A8 or an unused component) so the stride is a multiple of 4

stride3d/stride · error · ArgumentException

The vertex stride is not a multiple of 4 bytes

Error message

The vertex stride is not a multiple of 4 bytes

What it means

VertexElementValidator.Validate requires the vertex stride to be a multiple of 4 bytes, matching GPU vertex-buffer alignment requirements. A stride of e.g. 6 or 10 bytes is rejected with ArgumentException before any buffer is created.

Solutions

Add a padding element (e.g. an R8G8B8A8 or an unused component) so the stride is a multiple of 4
Widen an undersized element format (e.g. R8_UInt to R32_UInt)
Recompute the stride as the sum of element Format.SizeInBytes and pad to the next multiple of 4

Example fix

// before
// elements: R16G16 (4) + R16 (2) => stride 6
// after
elements: R16G16 (4) + R32 (4) => stride 8

Defensive patterns

Strategy: validation

Validate before calling

int stride = elements.Sum(e => e.Format.SizeInBytes);
if (stride <= 0 || (stride & 3) != 0)
    throw new ArgumentException("Vertex stride must be a positive multiple of 4 bytes");

Try / catch

try { VertexElementValidator.Validate(stride, elements); } catch (ArgumentException ex) { padLayoutTo4Bytes(); }

Prevention

Pad vertex layouts to a 4-byte-aligned stride
Avoid odd-sized trailing elements like a lone R8
Compute stride from Format.SizeInBytes sums, not from C# struct size

When it happens

Trigger: Building a VertexBufferBinding/vertex declaration whose summed element sizes total a non-multiple of 4, e.g. three R16G16 elements (6 bytes) or adding a single R8 element to a 9-byte stride.

Common situations: Compact packed vertex layouts (byte-based colors, 16-bit normals) that don't pad to 4 bytes; hand-computed strides missing padding.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/43366ae40f13bf85. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Graphics/VertexElementValidator.cs:65

    /// <exception cref="ArgumentOutOfRangeException">
    ///   <paramref name="vertexStride"/> is not a positive number greater than zero.
    /// </exception>
    /// <exception cref="ArgumentException">
    ///   Thrown if:
    ///   <list type="bullet">
    ///     <item><paramref name="vertexStride"/> is not a multiple of 4 bytes.</item>
    ///     <item>Any Vertex Element extends beyond the bounds of the vertex stride.</item>
    ///     <item>Any Vertex Element has an offset that is not a multiple of 4 bytes.</item>
    ///     <item>Duplicate Vertex Elements are found with the same semantic name and index.</item>
    ///     <item>Any Vertex Element overlaps with another element.</item>
    ///   </list>
    /// </exception>
    internal static void Validate(int vertexStride, VertexElement[] elements)
    {
        ArgumentOutOfRangeException.ThrowIfNegativeOrZero(vertexStride);

        if ((vertexStride & 3) != 0)
            throw new ArgumentException($"The vertex stride is not a multiple of 4 bytes", nameof(vertexStride));

        // For checking overlaps, we use an array to track occupied bytes
        var overlapCheckArray = new int[vertexStride];
        for (int i = 0; i < overlapCheckArray.Length; i++)
            overlapCheckArray[i] = -1;

        int totalOffset = 0;
        for (int elementIndex = 0; elementIndex < elements.Length; elementIndex++)
        {
            // Compute the offset for this element
            int elementOffset = elements[elementIndex].AlignedByteOffset;
            if (elementOffset == VertexElement.AppendAligned)
            {
                elementOffset = elementIndex == 0 ? 0 : totalOffset + elements[elementIndex - 1].Format.SizeInBytes;
            }
            totalOffset = elementOffset;

            // Validate the element offset

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