How to projection map a room: walls, TV, shelves and corners from one projector

Learning how to projection map a room is mostly learning to see your room as a set of shapes. A living room wall isn't one big screen. It's a wall, a TV, a sideboard, a picture frame, maybe a corner. Map each of those on its own and light lands on them as if it knows they're there. In the clip beside this article, one projector and an iPhone running EasyMapper Studio turn an ordinary TV wall into a show: candy falls and lands on top of the real TV, with no laptop anywhere.

Here's the whole process, from where to put the projector to what to play.

• A projector. Any projector with HDMI, or one that supports AirPlay. For a dark living room, 500 to 1,000 lumens is plenty. The lumens guide explains when you need more.
• An iPhone or iPad. EasyMapper Studio runs on iOS 15.1 or later and does the mapping and the playback, so there's no computer in the setup.
• A cable or AirPlay. A USB-C or Lightning to HDMI adapter, or AirPlay to a projector or Apple TV.
• A dark room. Projection mapping is light on a surface, so the darker the room, the stronger it looks. Evening with the lamps off is ideal.

Put it opposite the wall you want to map, far enough back that the beam covers everything you want to light. A shelf, a side table or a tripod behind the sofa all work. A few rules make the mapping easier:

• Face the wall as squarely as you can. Corner pinning fixes angles, but the closer to square you start, the sharper the result.
• Keep it out of the way. People walking through the beam cast shadows on the show. Higher and behind the seating is best.
• Fix it in place. Once you've mapped, a bumped projector shifts every surface. Tape or a small mount saves re-doing the work.

Then connect your phone. The connection guide shows the adapters and the AirPlay route.

Work from big to small:

1. Map the wall. Add a layer and drag its four corners to the edges of the area you want to light. This is your background.
2. Map the objects. Add a layer for each object on that wall: the TV, a shelf, a frame, a door. Drag each layer's corners onto that object's real corners.
3. Check from the sofa. Sit where people will watch and nudge any corner that doesn't sit exactly on its edge.

While you work, each empty layer shows a grid, so you can see exactly where it sits on the real object. Curved things like a round mirror can be fitted with a curved warp instead of four straight edges. Anything you don't want lit, like the TV screen itself, can stay black or be masked out.

This is where a mapped room beats a projector pointed at a wall, because every surface can play something different:

• Videos and photos. Anything in your camera roll can play inside a layer, fitted to that surface.
• Live shaders. Moving patterns that look good on any shape and never repeat exactly.
• Room effects. EasyMapper Studio's room effects treat every mapped surface as solid. In Pumpkin Drop or Spooky Emoji things fall and pile up on your TV and shelves, Bat Swarm and Ghost Swarm fly around them, and a Skeleton walks along their top edges.

The candy in the clip lands on the TV because the TV is a mapped layer. The interactive Halloween projection effects article goes through each effect.

Corners are the most fun surface in a room, because two walls meeting at a line can be turned into a 3D illusion. Map a layer on each wall so they meet exactly on the corner line, add a diamond-shaped layer above them, and the corner becomes a cube that seems to stick out of the wall.

The 3D projection mapping guide shows the cube step by step.

Can I map a whole room with one projector?

One projector lights what's in its beam, which in most rooms is one wall or one corner. That's usually the right place to start. To cover more walls you'd add a second projector and a second iPhone or iPad, each mapping its own wall.

Do I need projection mapping software on a computer?

No. EasyMapper Studio maps and plays from the phone. Free and paid desktop tools exist too; the free projection mapping software guide compares them.

How long does it take to map a room?

A first wall with three or four surfaces fits easily into one evening, and most of that is nudging corners. Saved mappings come back exactly as you left them, as long as the projector hasn't moved.

Does it work in a bedroom or a small apartment?

Yes. A short wall with a bed headboard, a wardrobe or a desk works just like a living room. The projection mapping ideas at home article has more surfaces to try.

Pick one wall tonight: open EasyMapper Studio, map the TV, and see what lands on it.