BEPUphysics
VelcroPhysics
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BEPUphysics | VelcroPhysics | |
---|---|---|
5 | 3 | |
2,158 | 649 | |
3.2% | - | |
8.7 | 1.8 | |
4 days ago | over 2 years ago | |
C# | C# | |
Apache License 2.0 | MIT License |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
BEPUphysics
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Current state of 2D game code-first frameworks?
The best pure-C# physics library (hands-down) is bepuphysics2, which unfortunately is mainly a 3D physics library, but could be used for 2D if you wanted to get your hands dirty.
- Physics Engine
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Open Source C++ Physics Libraries for Dedicated FPS Server?
Bepu Physics is pretty good and is written in really optimized C#, the author's blog post are really interesting to read.
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GJK: Collision detection algorithm in 2D/3D
The usual approach is some form of sweep to get a time of impact. Once you've got a time of impact, you can either generate contacts, or avoid integrating the involved bodies beyond the time of impact, or do something fancier like adaptively stepping the simulation to ensure no lost time.
If the details don't matter much, it's common to use a simple ray cast from the center at t0 to the center at t1. Works reasonably well for fast moving objects that are at least kinda-sorta rotationally invariant. For two dynamic bodies flying at each other, you can test this "movement ray" of body A against the geometry of body B, and the movement ray of body B against the geometry of body A.
One step up would be to use sphere sweeps. Sphere sweeps tend to be pretty fast; they're often only slightly more complicated than a ray test. Pick a sphere radius such that it mostly fills up the shape and then do the same thing as in the previous ray case.
If you need more detail, you can use a linear sweep. A linear sweep ignores angular velocity but uses the full shape for testing. Notably, you can use a variant of GJK (or MPR, for that matter) for this: http://dtecta.com/papers/jgt04raycast.pdf
If you want to include angular motion, things get trickier. One pretty brute forceish approach is to use conservative advancement based on distance queries. Based on the velocity and shape properties, you can estimate the maximum approaching velocity between two bodies, query the distance between the bodies (using algorithms like GJK or whatever else), and then step forward in time by distance / maximumApproachingVelocity. With appropriately conservative velocity estimates, this guarantees the body will never miss a collision, but it can also cause very high iteration counts in corner cases.
You can move a lot faster if you allow the search to look forward a bit beyond potential impact times, turning it into more of a root finding operation. Something like this: https://box2d.org/files/ErinCatto_ContinuousCollision_GDC201...
I use a combination of speculative contacts and then linear+angular sweeps where needed to avoid ghost collisions. Speculative contacts can handle many forms of high velocity use cases without sweeps- contact generation just has to be able to output reasonable negative depth (separated) contacts. The solver handles the rest. The sweeps use a sorta-kinda rootfinder like the Erin Catto presentation above, backed up by vectorized sampling of distance. A bit more here, though it's mainly written for users of the library: https://github.com/bepu/bepuphysics2/blob/master/Documentati...
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Early Demo of Dynamic Blocky Lighting System
I use https://github.com/bepu/bepuphysics2. I haven't worked with 3d physics engines before so I can't really comment on it's quality but it is definitely an impressive project! The developer is very active and helpful and some of the demo scenes are pretty large and complex.
VelcroPhysics
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How easy is Monogame for a beginner coming from game engines?
MonoGame abstracts a lot of the rendering work and is easy to use for 2D games (I haven't tested its 3D support so far). It also provides you with a content pipeline plus audio and input handlers. All that's left for you to do is roll your own Entity Component System, physics, and game logic. If you're not interested in writing your own physics, there are libraries out there already. Additionally, if you don't want to get caught up in the details of data serialization, Json.NET is a great package for serializing data in JSON format. That makes it perfect when paired with a map editor such as Tiled, which can export to JSON.
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Are things like colliders already built-in or should I program “everything” in Monogame?
Back in my indie days, I shipped a few 2D games with the Farseer physics engine on XNA to Xbox 360 and Windows phone. It's not dead either, the project lives on as Velcro Physics.
- Jeg har COVID selvom jeg er vaccineret. AMA.
What are some alternatives?
JoltPhysics - A multi core friendly rigid body physics and collision detection library, written in C++, suitable for games and VR applications.
pymunk - Pymunk is a easy-to-use pythonic 2d physics library that can be used whenever you need 2d rigid body physics from Python
Stride Game Engine - Stride Game Engine (formerly Xenko)
PhysicsExamples2D - Examples of various Unity 2D Physics components and features.
MonoGame - One framework for creating powerful cross-platform games.
ai2thor - An open-source platform for Visual AI.
Xenko
2DFPhysics - 2D fixed-point physics for Unity (WIP).
Nez - Nez is a free 2D focused framework that works with MonoGame and FNA
MonoGame.Extended - Extensions to make MonoGame more awesome
osu-framework - A game framework written with osu! in mind.