What is the best way to optimize game physics and collision for a better user experience?

To optimize game physics and collision for an enhanced user experience, focus on simplifying collision geometry by using basic shapes, implement level of detail (LOD) techniques to reduce calculations for distant objects, employ continuous collision detection for fast-moving objects, and utilize efficient culling methods to limit the number of objects involved in calculations. Choose a well-optimized physics engine, offload calculations to separate threads or processes, manage memory efficiently, and use collision layers to filter interactions. Regular profiling and testing are essential to identify and address performance bottlenecks, ensuring a smoother and more immersive gaming experience.

You can also have different levels of detail for the physics calculations. Objects that are far from the player or less visible might not need the same detail in physics calculations that those that are close and in focus.

Low-poly convex meshes are great, but in some occasions you might prefer having multiple small convex meshes instead of a single one, being part of a rigid body where mass is better distributed for applying gravity. For example, an hammer, you expect the blade to hit the ground first because mass is more distributed toward it rather than the staff. It won’t affect performance to split your low-poly mesh in half because you pretty much have the same amount of triangles overall but you can do better physics simulation.

Simplified meshes ensure more precise collision detection, preventing objects from passing through each other or interacting in unrealistic ways.

Efficient Collision Detection: Utilize algorithms like Axis-Aligned Bounding Box (AABB) for quick identification of non-colliding objects. Simplified Physics Calculations: Employ simple shapes for collision and opt for optimized physics engines. Fixed Time Steps: Use fixed time steps in your update loop for consistent physics. Multithreading: Spread physics calculations across multiple CPU cores for enhanced performance. Code Optimization: Regularly check and optimize your game to fix performance issues. Simpler Mesh Colliders: Use basic colliders . Balance Accuracy and Performance: Aim for a practical balance between accuracy and smooth gameplay. User Feedback: Continuously gather user feedback and test to refine the gaming experience.

In my experience, choosing the right physics engine for a game involves meticulous research and evaluation of available options. Integrating the chosen engine can pose challenges, requiring careful consideration of how it fits into the existing codebase without introducing adverse effects. We must address potential performance issues, optimizing the engine to ensure seamless gameplay. Balancing the physics engine's capabilities with the game's requirements demands a delicate touch to achieve the desired level of accuracy and performance. I imagine that we must navigate the intricate task of harmonizing technology and creative vision for an immersive gaming experience.

Study and copy real world natural objects. It adds a special charm to the game when things behave naturally. Use what ever technology possible for that.

Its also essential know when to activate or deactivate the physics engine. I used a custom script to activate or deactivate the gravity and the simulation type whenever the object is far away from the player. And also when the object is stand still and not moving. Increase the drag so the object is not moving allot and so decrease heavy calculation and artifact. The script also should be structure as physics manager to control the simulation state of multiple object. That manager should also loop on object frame by frame, if the objects array is more then 20, use a small loop that run through a small section from the object array each frame. Balance should be tested to reach a good physics simulation and script calculation.

One thing I've found helpful in optimizing game physics and collision is leveraging layers and tags. These mechanisms provide a powerful means to categorize and identify game objects, offering control over their interactions within the physics and collision system. By employing layers, objects can be organized into distinct groups like environment, player, enemy, and item. Tags further refine object properties, specifying attributes such as solid, trigger, or movable. This approach allows for precise control over which objects interact, streamlining the physics calculations. Layers and tags effectively reduce the need for superfluous collision checks, enhancing the overall efficiency and accuracy of the game.

Layers and tags are essential tools for streamlining game physics and collision. Categorize objects into layers like environment, player, enemy, and item, and assign tags to define properties (e.g., solid, trigger). For instance, label a player character as "player" and enemies as "enemy." By doing so, you can restrict interactions, reducing superfluous collision checks, and significantly enhancing performance and accuracy in your game, especially in scenarios involving diverse game objects and complex interactions.

Categorizing objects is essential for bigger projects. It not only helps with organization, but you can also be used to disable interactions between certain types of objects. Saving a lot of processing in that would be used for useless collision calculations

You can split your world geometry using layers, such as most geometry is used for rendering and very detailed near the camera, but having a separate layer for physics, mainly collision detection, with minimal geometry. If you have to do some raycasting then you should be using that specific layer to test against for better performance. Knowing where in your world collision meshes are required is probably part of another discussion but I think we can agree that we should not be having very high resolution meshes when not needed for physics.

Depending on the game engine, it become handy to know which layer is used for physics and which are not. By setting those layers carefully, it will optimize the physics calculation to the half. Also assign the object layer from one that doesn't use physics to one that use physics in runtime could help to make things more organized and with less script impact on performance.

I find this very insightful, as the insights drawn from this approach include the realization that incorporating raycasting and triggers significantly enhances the flexibility and precision of game physics. Raycasting, with its ability to detect intersections, enables the implementation of custom logic for measuring distances, angles, and object states. Meanwhile, triggers, as specialized colliders, provide a mechanism for event-driven interactions without inducing physical reactions. These techniques empower developers to create dynamic and interactive game scenarios, allowing for the activation, deactivation, or specific responses based on object interactions.

Raycasting and triggers are powerful tools for optimizing game physics and collision. Raycasting allows you to precisely detect object intersections along a specified path, providing control over interactions. Triggers, on the other hand, enable you to create custom collision logic without physical reactions. For example, you can use raycasting to calculate distances and angles for object interactions or triggers to activate events like opening doors. These techniques enhance game dynamics and interactivity while reducing unnecessary physics computations, leading to smoother gameplay experiences.

Raycasting is great for saving resources, it allows you to perform collision detection only when necessary. Instead of having every object in the game constantly checking for collisions.

In addition to rays, the use of AABBs (axis-aligned bounding boxes) and tree structures (Quadtree, Octree, RTree, etc.) are sometimes necessary in dense world simulation to avoid as much computation. Due to the algorithm of raycasting requiring to return, if any, the closest distance to the ray origin of any hit, it can be expensive to do a ‘brute force’ loop in situations like I mentioned above. By splitting the work in two passes, first using space partioning structures or ray-aabb testing; the second pass doing the actual ray-triangle tests on geometry, we can better scale the performance.

When having a lot of objects in the scenes, it become too heavy for the game to handle all the raycast and triggers in the scene, using a manager script to divide all the heavy work from one frame to multiple frame is a good practice. Also by decrease the fixed update time will be very handy for optimization.

Testing and debugging are critical to fine-tune game physics and collision. Ensure comprehensive testing across diverse platforms and devices to identify and resolve errors and bugs. Utilize debugging tools like debug logs, profilers, and breakpoints to monitor and analyze performance. For example, test your game on multiple VR headsets to verify optimal collision and physics interactions in a variety of scenarios. Continuous testing and debugging are essential for delivering an optimized user experience by addressing issues that could impact gameplay quality or immersion.

Testing and debugging has to happen for ANYTHING to run. More working against it to fail then running at all. Takes more time to fine tune and debug then it does to design the first run test. The number of ways to make applications more efficient are limitless.

focus on optimizing game physics by fine-tuning algorithms, leveraging parallel processing, and implementing efficient collision detection for an enhanced user experience

Use analysis tools like logcat, profiler, ...etc to recognize which is taking the heavy performance of the device, this could get tricky sense every device has its own specifications. Its good to take the most weak device for the test and debug. Optimization should be considered from the beginning of the development cycle because it could be impossible to edit the game feature after getting far away in development. Consider to develop every new features in small test scene before integration with the main scene to check compatibility and performance balance.

Games that can be palyed on different platforms like windows OS, andriod and iOS need to be tested thoroughly for cross platform integrations and configurations.Functional, regressiona and load testing are the most important one to take into account when it comes to gaming industry.

In addition to the mentioned considerations, it's crucial to think about the scalability and potential for future expansion of your game. As your user base grows and technology evolves, the demands on physics and collision systems may change. Therefore, design your systems with scalability in mind and remain adaptable to future improvements and updates. Additionally, consider accessibility options for a broader user base, accommodating players with different abilities. By embracing inclusivity and being prepared for potential growth, you can optimize your game physics and collision for a continuously better user experience.

As with anything related to optimizing, ask yourself, do I need this? I recently saw a video where the developer was asking why most games have dead units despawn at some point, the answer is ragdoll physics. But in some cases (like the WW1 setting of the game in question) it would be better to turn off the physics at some point, and then it won't take the computational overhead but still make the point the developer was trying to.