When an image is imported, it is converted to a square shape.

Hi @KYO＿WA,

Thanks for the question.

Due to how graphics processing hardware performs its computations, all the assets in the graph have power of two dimensions.

This is also why the final outputs are always 2048x2048, 4096x4096, etc., and not random numbers. Therefore, when you import a bitmap, it will have the same restrictions, and Substance Designer will stretch the image to fit the closest power of two.

With that being said, it's perfectly possible to have a non-square ratio image. In the Output size parameter of the node, change the Width/Height value in order to get a rectangle. As long as your bitmap isn't natively a power of 2, the image will always be stretched, but it can help making it less obvious.

I advise you to take a look at our documentation on the subject, I'm pretty sure this will interest you.

Best regards,