Collider

[mike2d]

hi,

i've put a cube in my scene with collider and rigidbody and i added an animated sprite onto it with its collider and rigidbody too.

when i hit play, the sprite goes through the cube a couple of pixels instead of sitting on top of it.

how can i fix that ?

[unikronsoftware]

If your ortho size is small (around 1), Unity's collision system with the default parameters will penetrate slightly. If you want to avoid this, you'll have to either change physics settings in Edit > Project Settings > Physics, or change the ortho size of the scene (and the ortho size in the sprite collection to compensate for this too).

[mike2d]

my camera ortho was set to 1.8 indeed, but now it is at 5 and still the same problem...

[mike2d]

ho wait, there's a tk2d camera round here 

but now my game panel doesn't show anything with this camera

i can see my scene in the camera preview (when the tk2d camera is selected) but nothing appears in the game panel...

[unikronsoftware]

Verify that this is indeed the problem first...
Edit > Project Settings > Physics

Set "Min penetration" to something a lot smaller, like 100x smaller  - 0.0001 and see if it makes things better.

[unikronsoftware]

ho wait, there's a tk2d camera round here 

but now my game panel doesn't show anything with this camera

i can see my scene in the camera preview (when the tk2d camera is selected) but nothing appears in the game panel...

Don't bother with the tk2dCamera in this particular case, that will skew the physics the other way.

[mike2d]

nice, the min pen. did the trick, thanks

so what's the purpose of the tk2d camera then ?

[unikronsoftware]

The tk2dCamera has 1 world unit = 1 pixel. Its useful for arranging UI elements or in any other case where this is useful. When physics is enabled though, the number of units vertically changes depending on resolution, and as such won't be as useful on a physics based scene. It may be exactly what you want though, depending on what you're after.

[mike2d]

ok thank you !

[daklab]

So what is the best practice for 2D physics mobile games when using tk2d? Is it to use two cameras in the scene: 1 tk2d camera for rendering UI and then 1 ortho camera set similarly to the tk2d_demo - Polygon Colliders demo - to render a physics scene?

Are there any "penalties" or performance issues I should be aware of if I simply want to use the tk2d camera for both my UI and for rendering my physics scenes?

If done this way what is the preferred setting for Edit > Project Settings > Physics > Gravity (say for a 800x480 target resolution)?

Thanks to anyone who can drop some tk2D knowledge, I just purchased it last night

[unikronsoftware]

That could work well. There won't be any significant performance loss if you use 2 cameras or 1.
If you want to use the tk2dCamera for both UI & rendering, you can work out the gravity, etc. by how many pixels you want to represent 1 meter. The default gravity will treat 1 pixel as 1 meter.