I am starting to work on a 2d top down tile-map game for fun and learning purposes. I have read some great answers here re tile-map size vs character sprite size, pixel density, ppu, screen resolution etc.

A standard route is to set a constant PPU and do characters as 2 tiles (vertically usually). We went with 32x32 pixels for the tile and 32x64 for the character.

Unfortunately, our artist didn't draw the character to fill out that space on the extremes (the feet and head do not touch the vertical edges and there is also space between the character and the horizontal edges) and when Unity slices the sprite-sheet we get smaller characters of 28x53.

I imagine this is a problem for keeping the consistency I outlined above with the tile size.

Is this a problem? If so, are the solutions to this to either change the tile size to 28x28 or ensure that the sprite design actually fills the tile space (that is, touching edges of the 32x64 area)? Must one draw items as always filling out the full tile size or can one make, say potions, in a 32x32 tile but only take up say 12x16?


1 Answer 1


No, this is not a problem.

If you make your character only 24 pixels wide for example (three quarters of 32), with a Pixels Per Unit value of 32, then Unity will default to sizing it 0.75 units wide (three quarters of 1 unit), and all your sprite pixel densities will still match just fine.

What PPU controls is pixel density, not the absolute width or height of the sprite, which you're free to vary and mix & match over any range you want.

Have you observed any issues with this that you'd like help correcting?

  • \$\begingroup\$ I have not yet, this was a pre-emptive concern. The correspondence between the character's pixel area and how many world units they take up is clear and very intuitive and I knew that PPU only controlled pixel density but I was unsure if having a character's width take up, say, three quarters of a world unit, was problematic (for whatever reason). So thanks for clearing that up! By the way, it was some of your great answers I was alluding to in my OP :) \$\endgroup\$ Mar 25, 2018 at 16:11

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .