Grapple & Go is a VR courier game. You fire a hook from each hand and swing through a rebuilt old town to drop off packages.
Then i thought that clinging to the wall would feel great, so I added climbing. This is how it went.
Reading the hands
The Quest 3 gives 26 joints per hand. I built a small gesture system on top of that. A pose is a set of finger rules: how curled each finger is, how close a fingertip is to the palm. Each rule has some wiggle room and a hold time. Hit all of them and you get an input.
A fork fires the grapple. A claw means grab. Hands bend a bit differently from person to person, so there is also an in-game recorder scene. You make a pose, snapshot it, name it.
Grab, anchor, pull
The climb is one loop. Hold a grab pose, touch a wall, and the hand sticks to that point. Each frame the body moves so the hand stays on the anchor. Pull your hand down and the body goes up. Open your hand and you drop, keeping the speed you built.
One hand holds your weight. Two hands let you go hand over hand.
Rigid arms
This is the same idea most VR games use. The arms are rigid. The hands are anchors. The body is the thing that moves.
Once it works that way, climbing is just one case of it. Any wall your hand presses into becomes leverage. Push a wall and you slide back. Hang from a ledge and you stay there, because the arm will not stretch. The body capsule is the hard limit, so you can climb and push and hang, but you never end up inside a wall.
Hang and grapple
You can hang off a wall with one hand and fire a grapple at another wall with the other. It tugs you toward it. Let go of the wall and you swing across.
I did not plan that move. It came out of the two systems sitting next to each other.
Things that fought back
Your hand disappears when you press it to a wall. The cameras cannot see it, so tracking drops and the grab let go. Now the grip holds through that and only releases when you open your hand.
The collision capsule pushed you off the wall. It is too wide to get close. It thins down while climbing, so you can get right up to the surface without clipping through.
The launch felt dead. It read your speed one frame too late, after you had stopped. Now it remembers the pull, so a fast release throws you.
Pulling onto a roof caught on the edge. Your standing height snagged the lip. So the capsule shrinks to about two thirds of your arm while you grip, then grows back when you let go on top.
Next
Per-player gesture calibration in the game, a screen to bind gestures to actions, and a more physical climb.
GRAPPLE & GO — project