Physics Rigidbody simulation

[Frooxius]

Add support for physics rigidbody simulation and related functionality. With the BEPUv2 upgrade nearing completion, I'm updating this issue to better explain what will actually be coming with proper Physics Rigidbody simulation.

With the upgrade (https://github.com/Neos-Metaverse/NeosPublic/issues/232) it is actually possible to get rigidbody-like behavior by unlocking rotation on the CharacterController. This is a lot of fun to play with, as it will mostly behave like actual rigidbody, but it's very important to understand its limitations.

This is because CharacterController under the hood is actually a rigidbody (typically with rotation simulation locked) with extra stuff for good character control. Now this extra stuff is part of what doesn't make them suitable for large scale simulations - they'll be glitchy, eat a lot of CPU and network bandwidth. They are optimized for different use-case:

Why character controllers aren't suitable for rigidbody simulations

• They're optimized for character locomotion and will have odd behavioral quirks when used otherwise, these will be addressed by the actual rigidbody support, so before that comes you'll have to deal with them
• Having many of them won't perform well, both on CPU and network. They're not optimized for this use case
• You have limited control. You can't control aspects like friction or create constraints (e.g. joining bodies with joints, hinges, motors etc) that actual rigidbodies support.
• We STRONGLY discourage building too complex long term content with this mechanism, other than one that involves actual character control.

Now if you understand these limitations, feel free to have fun with them in the meanwhile, before the full support actually comes. Neos is all about tinkering, toying around and messing with things and it will give you a bit of a taste of what will come.

Here are some examples of how the "proto-rigidbodies" behave: https://youtu.be/Oz8q7_GUDV4 https://youtu.be/8dQZjtt9t-4

What will full rigidbody support offer?

The full rigidbody support covered by this issue is a significant chunk of work that will come after the BEPUv2 upgrade completes. It will focus on following:

• CPU and network efficiency - with engine optimizations, efficient handling of many bodies in the simulation and specialized network encoding will allow you to have many bodies in the world with significantly lower impact Simple to use with less glitchiness - controlling the friction, bounciness, applying forces and impulses and more, without the extra “cruft” that character controllers have - these will be pure rigidbodies
• Constraints - you will be able to connect the rigidbodies with a number of constraints - joints, springs, hinges, motors and more, to create complex setups and interactions
• Smooth simulation and interaction for everyone - character controllers are simulated by a single user only and can be quite choppy and glitchy (for example when grabbing they just randomly poof off somewhere) for others if not setup properly. Full rigidbody support will be designed to not have these issues.
• New features and tools - instead of having to go through convoluted process to enable the simulation, we’ll add quick tools and integrate physical interactions across Neos, to make it very easy to start playing with them and building cool content

Make sure to also check the roadmap for physics support, we'll expand it with individual tasks once work begins on this (we're still finishing BEPUv2 upgrade at the moment, so it won't happen before then): https://github.com/Neos-Metaverse/NeosPublic/projects/19

[pushstartvr]

This sounds amazing, I could imagine this wouldn't be possible on mobile though? maybe make it an option in the "new world" dialogue

[Karel64]

Will allow for major Neos car and truck riding funtime! 😃

[Simulacron3]

And moon buggies and elevators and flying carpets! What is a world without gravity and the rest of physics?

[Frooxius]

Pre-requisite: https://github.com/Frooxius/NeosPublic/issues/232

[Frooxius]

With BEPUv2 upgrade nearing completion, I have updated the original post to better describe what's coming and why is this a separate issues - rigidbodies are coming as a separate chunk of work after #232 is completed, so do not expect them in the initial release!

Please give the original post a read if you can to better understand what's coming now and what will come at later point.