Niantic is using all the power of Apple's ARKit to make catching things in Pokemon Go a lot more fun. The new AR+ feature lets you sneak up and score some bonus Stardust and XP if you do it right, but it's not really designed to be used everywhere. There will be places where you are going to want to tap that AR+ toggle to turn this feature off, and return to the fully animated method of catching Pokemon.
Choosing where to use AR+ can be a bit confusing, but here's a quick rundown of all the places we've tested it so far.
Parks and Playgrounds are best
Any wide open space, especially where there's a big field or grassy area, is perfect for AR+ in Pokemon Go. The app functions best when the phone can easily "find" the ground and make some virtual Tall Grass appear. It also looks a little more natural, which helps make everything feel a little more real.
You don't necessarily need the grassy area to be super flat, but playing on the side of a steep hill may confuse AR+ a little. Just about any other grassy area will be perfect.
Avoid hallways and narrow spaces
AR+ uses Apple's ARKit technology to map out flat surfaces, and it does that really well. What it doesn't do particularly well is walls. You can play this game indoors if you've got a decently-sized living room, but smaller rooms and hallways are best to avoid. AR+ encourages you to move around a lot, and if there are walls in between you and your Pokemon you're going to have a bad time.
For the most part, playing indoors will mean tapping the AR+ toggle to off and using the fully animated mode.
Playing at night is tricky
You can use AR+ in well-lit spaces with no problem, but playing at night is going to be a bit of a mixed bag. Basically, if it's too dark the phone may not be able to clearly "see" the ground, which might make the Tall Grass not appear or appear slanted. If the Tall Grass doesn't appear you won't be able to catch the Pokemon, and if it appears slanted you may have more trouble throwing the ball just right.
Your experiences are going to vary quite a bit at night, so keep that in mind and have fun!