I'm reminded of the description in "Rainbow End?" where the guy doesn't have a VR setup yet and sees people reaching out and touching shapes held in the air by mechanical arms. Basically, there are 'self-arranging blobs' that arrive 'just in time' to your interaction, changing their tactile surface to reflect what you expect. The user sees none of this, and only what they see in their interface.

I can't imagine it working perfectly. Say, pulling a book out of a shelf should have exactly zero resistance (other than the force of gravity pulling the book down). Having near zero latency between action and the 'tactile interface' moving in exactly the right direction would be a very hard problem...

Ok now you’re running and your foot clips a rock. Think fast machine. Does a blob clip your foot and cause you to fall irl?

For some people, does the blob even need to be there for them to trip?

No, but there’s a big difference between the machine causing you to fall with force vs just falling on otherwise flat ground normally.

Yes, it should. That would be amazing.

Not sure how dangerous it has to get. Just having some basic motors that counteract the force you exert with a fast response time probably couldn’t do much damage. An intelligent system to also check that you maintain your balance (or only doing this seated) probably takes away a bunch of risk.

Objects in an immersive environment are not static and unmoving. Guy punches you in the face. What does the system do?

Seated is kind of stupid imo.

Well first are you wearing just haptic gloves or are you also wearing a mask? In the first case nothing would happen obviously. In both cases the system should be able to distinguish you exerting a force and matching a counteracting force to give a sense of pressure vs VR contact that can be simulated through significantly less force (eg a haptic buzz).

Then you’re back to the current state problem where it just buzzes

I imagine a force-feedback exo-suit that turns you into a mime, but with sensation. It won’t necessarily give you a punch in the face, but could afford resistance and virtual heft to some virtual objects, and would have been an interesting scene in an Iron Man movie.

I work on gloves like this, and that's really not what we see in the real world.

The active force applied to the fingers is actually pretty small. The geometry of a flexed hand gives huge mechanical advantage. The key is a large holding force. It's easy to prevent you from closing your hands further without needing to actually overpower you.

You don't need to pull hard, you just have to be able to stop hard. No real risk there.