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Ashwin
Ashwin

Posted on AI-assisted

I built a 3D globe where you can dig straight through the Earth

#javascript #webdev #showdev #threejs

I've been building a browser globe called Planet-X on my own. It has live radio, TV and webcams for every country. But the feature people keep coming back to is one I almost didn't ship.

It's called Dig. You pick a spot, dig straight down, and the camera shows you where you'd come out on the other side of the Earth. Try it: https://planet-x.world/dig

Most people come out in the ocean. If you want dry land, dig from Spain and you'll end up in New Zealand.

The math is almost nothing

The point opposite you is your antipode. Flip the latitude and shift the longitude by 180°:

function antipode(lat, lng) {
  return { lat: -lat, lng: lng > 0 ? lng - 180 : lng + 180 };
}

antipode(40.4168, -3.7038);
// Madrid → { lat: -40.4168, lng: 176.2962 }, on New Zealand's North Island
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The function was never the hard part. The hard part was the camera move into the ground, so it feels like one motion and not a teleport. I replaced a simple damped fly-to with a planned zoom-and-pan path (van Wijk & Nuij), and the globe stopped feeling like a map viewer.

What the launch taught me

I posted on Product Hunt and asked for unflattering feedback. Two comments changed what I did next:

  • Someone tapped a shared link and hit a login screen, even though exploring never needs an account. I removed it. A broken first impression costs more than a missing feature.
  • Someone said it took a while to understand what "dig to the other side" meant. A clever name doesn't help if people don't get it in two seconds.

I have about ten other features (Guess Where, a daily World Question, buried secrets you can only find by digging). My takeaway is that the hard job isn't building them. It's making the first ten seconds obvious.

The stack

Three.js, Vercel and Supabase. Radio comes from the community-run Radio Browser directory, and I only show stations that are working and stream securely.

Two questions for you

  1. What confused you first?
  2. Where did you come out? I'm curious how many of you landed on land.

👉 https://planet-x.world/?ref=devto

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