Note: Using Graphics.ConvertTexture

A note on using Unity’s Graphics.ConvertTexture.

Graphics.ConvertTexture()

Graphics.ConvertTexture in Unity can be used to change the format of/resizing Texture2Ds. But there’s one tiny problem.

The issue

The converted texture is stored in the GPU. If you try to use GetPixels or GetPixels32 on the texture in your script, it will return a completely grey texture. You have to copy the texture into the CPU. And, unlike what the Unity documentation says, there is no function called Texture2D.RequestIntoNativeArray.

The fix

Use AsyncGPUReadback.RequestIntoNativeArray. This is what I’m using to resize a texture:

// Don't forget to define texture, newWidth and newHeight.

Texture2D scaled = new(newWidth, newHeight);

// Convert the texture.
Graphics.ConvertTexture(texture, scaled);

// Create an array to store the texture.
NativeArray<float> nativeArray = new(newWidth * newHeight * sizeof(float), Allocator.Persistent);

// Start the operation to read the texture from the GPU.
AsyncGPUReadbackRequest request = AsyncGPUReadback.RequestIntoNativeArray(ref nativeArray, scaled);

// Wait till it's done.
while (!request.done)
    await Task.Yield();

// Check for errors.
if (request.hasError)
{
    // Dispose the array.
    nativeArray.Dispose();
    return null;
}

// Load the texture.
scaled.LoadRawTextureData(nativeArray);

// Dispose the array.
nativeArray.Dispose();

return scaled;

I have no idea if what I’m doing here is performant, but it works.