Rigid body dynamics: Resting contact

[epaik91]

I'm currently programming a 2D rigid body dynamics engine.

While I have realistic collision detection and response between polygons, I have trouble in the simulation once I implement gravity.

When these rigid bodies are influenced by gravity, they never fall to complete rest (e.g. they always retain some kinetic energy and keep bouncing around). Additionally, when several bodies are on top of each other, my separating algorithm fails and the bodies interpenetrate a little.

I need to figure out a way to implement resting contact forces. Any advice would be appreciated.

 

[cesiumfrog]

That's a common problem, I suggest that you search out some of the existing technical papers on the subject. Let us know how it goes. (If I were fiddling with this again, I'd try either slightly non-rigid bodies or exact non-iterative solutions to the motion).

 

[astrokreng]

It sounds like you are facing some challenges in accurately simulating rigid body dynamics in your 2D engine. First, it's important to understand that the behavior of rigid bodies in a simulation is influenced by various factors such as the accuracy of the simulation, the time step size, and the type of integration method used.

In order to accurately simulate resting contact, you will need to consider both the forces acting on the bodies and the constraints placed on them. For example, when two bodies are in contact, there are normal forces acting between them that keep them from interpenetrating. Additionally, friction forces may come into play depending on the materials and surfaces of the bodies.

To accurately simulate these forces, you may need to consider using more advanced algorithms such as impulse-based collision response or constraint-based methods. These methods take into account the forces and constraints acting on the bodies in order to accurately calculate their motion and behavior.

Another important aspect to consider is the accuracy of your collision detection. If your collision detection is not precise, it can lead to incorrect calculations and unstable behavior in the simulation. Make sure to thoroughly test and refine your collision detection algorithm to ensure accurate results.

In summary, accurately simulating resting contact in rigid body dynamics requires a combination of precise collision detection, advanced algorithms for handling forces and constraints, and careful consideration of factors such as time step size and integration methods. I would suggest researching and implementing these techniques in your engine to improve the accuracy and stability of your simulations.