Collision Detection u0026 Response Quiz Quiz

Challenge your understanding of collision detection techniques, response strategies, and key terminology used in computer graphics, simulations, and game development. Explore essential concepts like bounding volumes, discrete and continuous detection, and resolution methods with real-world scenarios.

1. Bounding Volumes in Collision Detection

   Which bounding volume is most efficient for detecting collisions in a group of axis-aligned rectangular objects in a 2D space?

   1. Bounding Sphere
   2. Convex Hull
   3. Oriented Bounding Box (OBB)
   4. Axis-Aligned Bounding Box (AABB)

   Explanation: Axis-Aligned Bounding Boxes (AABB) are optimal for axis-aligned rectangles due to their simple calculations and low computational cost. Oriented Bounding Boxes (OBB) are better for rotated objects but unnecessarily complex here. Bounding Spheres are less tight-fitting for rectangles, potentially causing inaccuracies. Convex Hulls provide the most precise fit but demand more resources to compute. For axis-aligned rectangles in 2D, AABBs offer the best balance of speed and accuracy.

2. Continuous vs. Discrete Collision Detection

   In a fast-paced simulation, why might continuous collision detection be preferred over discrete collision detection when moving a small object quickly across the screen?

   1. Because discrete detection works only in three-dimensional spaces
   2. Because continuous detection uses less memory than discrete methods
   3. Because continuous methods can detect tunneling caused by fast-moving objects
   4. Because discrete methods always detect every collision exactly

   Explanation: Continuous collision detection addresses the tunneling problem, where fast objects pass through others between frames. Discrete methods may miss such collisions if an object moves too far in a single step. Continuous methods are typically more computationally intensive, not less, than discrete methods. Discrete detection applies to both two- and three-dimensional spaces, not just three-dimensional ones.

3. Collision Response Techniques

   After detecting a collision between two billiard balls in a simulation, which response algorithm is commonly used to update their velocities based on momentum conservation?

   1. Euler integration
   2. Axis clipping
   3. Separating axis theorem
   4. Impulse-based response

   Explanation: Impulse-based response calculates the change in velocity for colliding bodies by applying sudden forces, ensuring momentum and energy conservation as required. Axis clipping and the separating axis theorem are techniques used primarily for collision detection, not response. Euler integration is a numerical method for advancing object positions over time and does not solve for physical response to collisions.

4. False Positives in Collision Detection

   What is a potential drawback of using simple bounding spheres for collision detection around detailed polygonal vehicles in a racing game?

   1. Bounding spheres require extensive computation for each polygon
   2. Bounding spheres alter the actual geometry of the vehicle
   3. Bounding spheres never detect any collision between objects
   4. Bounding spheres may produce false positives by overlapping when objects are not actually touching

   Explanation: Bounding spheres can produce false positives because their simple shape often overlaps when the detailed geometry within does not. While bounding spheres are computationally efficient, they do not require per-polygon calculations or alter the underlying vehicle geometry. They do detect collisions, but sometimes detect contact where none exists due to their approximate fit.

5. Broad Phase and Narrow Phase Distinction

   In collision detection systems, what is the purpose of the broad phase step before narrow phase calculations?

   1. To quickly eliminate pairs of objects that cannot possibly collide
   2. To interpolate object positions smoothly for rendering
   3. To precisely calculate the penetration depth of overlapping objects
   4. To simulate friction and restitution effects after collisions

   Explanation: The broad phase step filters out object pairs that are too far apart to interact, reducing the number of costly narrow phase collision checks. The narrow phase is responsible for precise calculations, such as penetration depth. Collision response for friction and restitution happens after detection, and smooth interpolation of positions pertains to rendering, not collision tests.