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Comment by jallen_dot_dev | Hacker News Reader

> The functionality seems at first glance to be a given for any game with a similar environment, but according to an observation by naoya2k, what makes Nintendo’s solution unique is that there are no physics working between Link and the dynamic object. Since both the character and object use physics, the most straightforward solution would be that Link moves together with the moving objects he is on top of as a result of physics (such as frictional force), but Nintendo apparently decided that what works better game-wise is Link being given the same movement that the object is performing, without any physics working between the two.

No way this is the first game to ignore the player character in physics calculations. I'm pretty sure in GTA3 you could climb onto the roof of a car and not slide around as the NPC drives and makes sharp turns.

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That's just a trivial parent-child transformation copy, and it's one of the oldest tools in 3D digital representation. You would be hard-pressed to find a game engine or even modeling software without this feature. Hell, I'm sure if you looked through a few geometry or physics books, you could pretty easily find any instance of this that predates computing.

We aren't even talking about something interesting like inverse kinematics!

This patent boils down to nothing more than math, and should have been invalidated as soon as it was read. The fact that it wasn't speaks volumes on the failure of our patent system.

> should have been invalidated as soon as it was read.

And anyone named in the patent or sponsoring anyone named in the patent prevented from applying for any new patents for 10 years.

If I understand the issue correctly:

Uncharted 2, (or 3?) on the PlayStation, was widely publicized among game developers as having this kind of technology built into enable for instance the Nathan Drake character to stick appropriately to platforms which were being tossed around in a sinking ship. The ship was filling up with water creating buoyancy for the platform that he was standing on. There were numerous talks about this and I believe also a GDC presentation about it.

Another example could be: in Tribes, when you pilot a vehicle your player character gets attached to a mount point and any physics calculations are ignored.

I'd imagine nintendo probably have other claims linked to this since alone it has clearly been done before.

I have fond memories of playing Tribes on call center PCs when we got snowed in at the office in a mid-day snowstorm.

Pretty sure this is the default Character implementation in unreal engine.

There is nuance to what constitutes “standing” on the object.

I think most games that use detailed physics include optimizations like this.

I think the point is that the approach far predates games with anything like a physics system. That part of the patent seems to describe what happens when a character stands on a moving platform like an elevator. This stuff predates Super Mario Bros.

Typically something like an elevator wouldn't be modeled with physics (mass, velocity, etc.) its movement would just be hardcoded. And of course games without a physics emulator wouldn't do that either.

My understanding of the patent is that two objects that are normally subject to physics (the player and a platform), when the player stands on an object the player's physics are disabled and the player's position is just copied from the object.

But, like, there's no way this hasn't been done before.

I agree fully.

I’m pretty sure the source engine has this builtin

Even the original Half-Life monorail intro sequence had the player moving relative to a moving vehicle.

You weren't moving on a simulated rigid-body physics object, but in practice there's not much difference - other than handling the nasty cases, like what to do when the physics object flips upside down and crushes the player, or resolving collisions with static world objects that the player makes contact with but the 'vehicle' doesn't.

In HL1 you fly to the back of the tram when you jump because you only move with it while grounded. In HL:Source you move with the tram correctly and jump in place relative to the tram. Bafflingly in Black Mesa it's back to the incorrect HL1 behavior. Always bothered me.

This has existed in Unreal Tournament 2003 where players can ride another player's vehicle simply by standing on it.

Or like every 2D platformer ever?

Not quite. It’s pretty rare to be jumping off and standing on top of moving physics objects in 2D platformers. Like in Mario almost everything you can stand on is static or following a fixed movement pattern.

I'm also wracking my brain for this situation in one of the many metroidvanias I've played. There are many which let the player freeze enemies so they can be used as platforms but the enemies are also not moving by that point.

The most likely I can think of is Axiom Verge, which has a mechanism for "glitching" enemies that might allow for a non-frozen enemy to be used as a platform while it continues to follow the player character around. I'm not totally familiar with how each enemy glitches so it's only "likely" in the sense that I don't know it's definitely not possible.

Physics objects are generally poor fits for 2D platformers. They’re random which betrays slick level design (and endangers sequence breaks in some games). They probably fall too fast to interact with. They potentially accumulate. 2D platformer characters tend to not experience physics aside from gravity to begin with and sliding momentum as they usually cannot rotate and don’t expect to encounter forces from collisions.

Can Mario fall into a thrown ice block and acquire its velocity while it’s moving midair without pushing the block down? I think he can technically. But it doesn’t show up as something you should expect to interact with. Maybe sliding along a surface but that’s barely a physics object.

Megaman X has an ice-skateboard that you can summon and then ride.

Could you find a video or reference to this? I can’t recall it.

https://youtube.com/shorts/qm5M0bt8VVI

My apologies that it's a youtube short. I couldn't find any better video.

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