stride3d/stride · error · InvalidOperationException

A texture with size [ ] already exist with the same output…

Error message

A texture with size [{0}] already exist with the same output size

What it means

Each output of an ImageMultiScaler must have a unique size, because the scaler keeps one output per size step. PrepareScaling throws InvalidOperationException when a newly added output texture has the same Size as one already registered in outputTextures.

Solutions

1. Give every output texture a distinct Size before adding it to the scaler.
2. Fix size-computation loops so consecutive outputs differ (check integer rounding: Math.Max(1, size >> level) collisions).
3. Check the message's size value and find the duplicate SetOutput call producing that dimension.

Example fix

// before
for (int i = 0; i < levels; i++) scaler.SetOutput(i, RenderTexture(w >> i, h >> i)); // level rounding may duplicate
// after
var used = new HashSet<Size3>();
foreach (var size in ComputeDistinctSizes()) if (used.Add(size)) scaler.SetOutput(...);

var seen = new HashSet<Size3>();
foreach (var o in outputs)
    if (!seen.Add(o.Size)) throw new InvalidOperationException($"Duplicate output size {o.Size}");

try { scaler.Draw(context); }
catch (InvalidOperationException) { Log.Warning("Duplicate multi-scaler output size; removing duplicate"); }

When it happens

Trigger: Adding two output textures with identical dimensions to the same ImageMultiScaler (e.g. two mip-like outputs both at half input resolution) and rendering.

Common situations: Loop-generated outputs with a rounding bug making two sizes collide (integer division); copy-pasted SetOutput calls using the same size texture; UI code that binds the same render target twice.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

• Unsupported texture size
• Input and output texture cannot have same size
• Custom strides is not supported with packed PixelFormats
• output
• Source texture is not a MSAA texture.

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/053cd428f90c6f30. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Rendering/Rendering/Images/ImageScaler/ImageMultiScaler.cs:154

                    if (inputSize == outputSize)
                    {
                        throw new InvalidOperationException("Input and output texture cannot have same size [{0}]".ToFormat(inputSize));
                    }

                    int newScalingDirection = outputSize.CompareTo(inputSize);
                    if (scalingDirection != 0 && Math.Sign(scalingDirection) != Math.Sign(newScalingDirection))
                    {
                        throw new InvalidOperationException("Support only output scaling to the same direction");
                    }
                    scalingDirection = newScalingDirection;

                    // Check that we are scaling to different texture sizes
                    foreach (var existingOutput in outputTextures)
                    {
                        if (existingOutput.Size == outputTexture.Size)
                        {
                            throw new InvalidOperationException("A texture with size [{0}] already exist with the same output size".ToFormat(existingOutput.Size));
                        }
                    }

                    // If the textrue is valid use it
                    outputTextures.Add(outputTexture);
                }
            }

            return outputTextures.Count > 0;
        }

        private Texture FindOutputMatchingSize(Size3 targetSize, int scalingDirection)
        {
            for (int i = 0; i < outputTextures.Count; i++)
            {
                var outputTexture = outputTextures[i];
                if (outputTexture == null)
                {

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