Ahh just found "Platform Specific Sprite Collections", I am going to check it out first....
If i up scale images from low to high resolution, output is pixelatted. If I down scale images from high to low resolution, older devices might not run the game due to memory constraint?
Based on assumption above ,I have a couple questions ....
1.Ideally I should create high and low images for each sprite?
2. Two atlas, one for retina devices, another for older devices?
If my assumption is correct, is there any demo scene I could study? For example I would like to know how to setup the scene so the engine would load the atlas correctly.