Overview
Broad phase collision detection uses simple bounds or spatial partitions to reduce the number of expensive pairwise checks.
CoreSource checked
Broad Phase Collision Detection
Quickly finds possible colliding object pairs before exact collision tests.
Quick Facts
Compact metadata for implementation and discovery.
- Category
- Simulation
- Difficulty
- Intermediate
- Family
- Collision Detection
- Tier
- Core
- Status
- Verified
- Review
- Source Checked
- Sources
- 1
- Formulas
- 1
- Relationships
- 7
- Code example
- Ready
- Visualization
- Ready
Core Concepts
candidate pairbounding volumespatial partitionpair pruning
Quick facts
Complexity
Runtime and memory behavior at a glance.
Best
O(n)
Average
O(n log n + k)
Worst
O(n^2)
Space
O(n)
When to Use
- Use when physics simulation needs candidate pair.
- Use when the input matches the assumptions behind collision Detection.
When Not to Use
- Avoid when the time step, forces, or constraints make the system unstable for the chosen method.
- Avoid when a simpler algorithm gives the required result with less setup.
What It Does
- Quickly finds possible colliding object pairs before exact collision tests
- Uses candidate pair and bounding volume to guide the work.
- Produces updated state.
Use Cases
- Physics simulation
- Animation
- Interactive systems
Inputs
- Current state
- Forces or constraints
- Time step
Outputs
- Updated state
- Constraint corrections
- Collision results
Key Formulas (1)
Pair pruning
test precise collision only if bounds overlap
test precise collision only if bounds overlapSends only overlapping bounds to the narrow phase.
Pseudocode
- 1.Prepare the inputs and state needed for Broad Phase Collision Detection.
- 2.Apply the candidate pair step while the stopping condition has not been met.
- 3.Update intermediate state and discard invalid candidates.
- 4.Return updated state.
Canonical Example
- Input
- 100 moving objects with bounding boxes
- Output
- small set of potentially colliding pairs
- Explanation
- The broad phase rejects objects whose bounding volumes cannot overlap before narrow-phase tests run.
Implementation Notes
- Use AABBs, grids, sweep-and-prune, or BVHs to cheaply reject distant objects.
- Pass only candidate pairs to narrow-phase collision tests.
- Track frame-to-frame updates if objects move continuously.
Common Pitfalls
- Reporting broad-phase pairs as confirmed collisions.
- Using a spatial partition that is poorly matched to object sizes.
- Forgetting to update bounding volumes after motion.
Interactive Mechanism Walkthrough
Iterative Convergence & State TrajectoryShow state updates, constraints, and error correction over simulation steps.
Step 1 of 4: Prepare the inputs and state needed for Broad Phase Collision Detection.
simulation-mechanismNotes
Broad Phase Collision Detection operates in O(n log n + k) time and O(n) space within the Collision Detection family. Key governing relation: test precise collision only if bounds overlap. Often compared with Narrow Phase Collision Detection and Sweep and Prune.
Sources (1)
What each reference supports for this entry.
Real-Time Collision Detection
BookReference for broad-phase and narrow-phase collision detection, bounding volumes, and geometric robustness.
Open sourceExplore Next
Good next jumps from the relationship graph, ranked for useful discovery.
UsesAxis-Aligned Bounding Box Intersection
Geometry · Foundation
Broad phase commonly uses bounding boxes for cheap overlap checks.
Compare with thisUsed byRigid Body Dynamics
Simulation · Core
Rigid-body simulation pipelines use broad phase to find possible contacts.
Compare with thisRelationships
View full relationship pageBroad phase commonly uses bounding boxes for cheap overlap checks.
Prerequisite ofNarrow Phase Collision Detection
Broad phase selects candidate pairs before precise tests.
Often paired withSweep and Prune
Sweep and prune is a common broad-phase strategy.
Related Algorithms
Tags
SimulationCollision DetectionBroad PhaseSpatial Index