Hi, I’m basically trying to understand more how unity scaling and pixel per unit system works. I’d like to understand why to have pixel perfect positioning (so that a single sprite represents an object whose bounds are respectively 1f wide on the x axys and 1f tall on the y) i need to put 32 on pixel per unit in the sprite menu.
I’m not asking for you to explain it, any reference / official guide is much more appreciated, since it seems I cannot find it by myself
For understanding this unit to pixel even though there is not much write up material available with the Unity that explains it but the principal actually applies to most of the game engines.
There is actually quite discussion about that over Box2D forums. One of the paragraphs states that:
Box2D physics objects are defined with
meters for length and width. Box2D is
tuned for a 1x1 meter sized objects.
The reason you want PTM (Pixels to
Meters) is that you do NOT want to
have a 1 to 1 correlation between
pixel size and meters size.For example if you had a car that was
200 pixels long and 50 pixels tall,
and you did not use a PTM conversion
you would end up creating a Box2D car
of 200 meters by 50 meters. That’s 656
feet long or about the length of 12
semi trucks. Imagine the force you
would have to apply to this car to
move it.
In short what you do is you just separate the rendering from the physics calculations.
And the same principle applies to Unity also since all the physics and calculations in Unity are done in its own system which is MKS itself so the same principle applies here.
If you want to understand how this actually works read this article: Pixels
Let us know if this clarifies your queries or anything else is required.