Is there any consequence if the sizing of your canvas is big or small?

May I ask is it of any consequence to have a smaller size(length and breath) 2D image, as compare to a larger size 2D image, if the resolutions are the same?

Say my canvas is 1920x1080, will it make a difference if I put it on iphone, andriod or ipad, considering I set the UI scale Mode to "Scale with Screen Size"?

One of my concern is also if I put the image file to be too big, the size of the entire game will also be big.

 

Yes, I think you've got it. If your images are bigger than they need to be, then your download is needlessly big. But if they're too small, then they may appear pixelated on larger screens.

 

Are we talking about the size of the image in the scene? Because that doesn't affect the actual size on disk.

 

I assumed we were talking about the number of pixels width and height in the image (or more precisely, in its import settings).

But yeah, if we're just talking about the size of the UI element, then that doesn't matter at all.

 

I'd be more concerned about aspect ratio. Mobile devices typically have very high resolutions for their size, so you'll often be stretching a 1920x1080 image to a higher resolution than it was created for. But you'll probably find it looks just fine on such a small screen anyways. What may end up being a problem is if the device doesn't use the same 16x9 aspect ratio. Depending on how your UI and game is set up, you may end up with images stretched in just 1 direction, black bars, UI elements in the wrong place, etc.

iPads use 4x3 or 23x16. iPhones use 19.5x9, 13x6, or 16x9. Android devices are the most varied, coming in pretty much any aspect ratio you can think of.