I am using Unity’s Sprite Packer. I was wondering if using ‘tight mesh’ sprites for mobile platforms is a good idea. Sure, tight mesh gets rid of the excess pixels and therefore, seems to be efficient size-wise, which will probably put less burden on RAM, but it adds a lot of triangles to the mesh.
Precisely;
Tight Mesh: 20+ triangles per sprite
Full Rect: 2 triangles per sprite
I have two high-end mobile devices to test and they don’t seem to have any problems dealing with tight meshes. But I don’t know if it would be the same with lower-end devices. Can anyone shed some light on this?
It all depends on how many seperate objects you will have at runtime. I guess unity will batch things in your case.
If you have just 20 sprites then 20 or 2 triangles does not make any difference. If you have 1000 sprites and they get batched it will still be no problem.
If unity batches all of them into one object/batch then you will need a very high number of sprites to cause any effect on speed.
I think there is a 64k triangles limit per object. with 20 triangles per sprite you can have 3000 of them without unity makeing another object/batch/drawcall out of it.
Have a look at the batch count rather than triangles. For lower end devices 40 batches should be the limit.
You could try to increase the sprite count in your game and see when your divices start to get slower. Just to get a feel for it.