v3.1 Release Notes

API Changes

• 64-bit filter categories and masks
• 64-bit dynamic tree user data
• Renamed b2SmoothSegment to b2ChainSegment
• Cast and overlap functions modified for argument consistency
• Contact begin events now provide the manifold
• More consistent functions to make polygons
• Contact events are now disabled by default
• Replaced b2Timer with uint64_t
• Shape material properties now use b2SurfaceMaterial

New Features

• New character mover features and sample
• Revised sensor system is now independent of body type and sleep
• Rolling resistance and tangent speed
• Friction and restitution mixing callbacks
• World explosions
• World access to the maximum linear speed
• More control over body mass updates
• Filter joint to disable collision between specific bodies
• Bodies can now have names for debugging
• Added b2Body_SetTargetTransform for kinematic bodies

Improvements

• Cross-platform determinism
• Custom SSE2 and Neon for significantly improved performance
• SSE2 is the default instead of AVX2
• Removed SIMDE library dependency
• Faster ray and shape casts
• Faster continuous collision
• Each segment of a chain shape may have a different surface material
• Reduced overhead of restitution when not used
• Implemented atomic platform wrappers eliminating the experimental:c11atomics flag

Bugs Fixes

• Many bug fixes based on user testing
• Fixed missing hit events
• Capsule and polygon manifold fixes
• Fixed missing contact end events
• PreSolve is now called in continuous collision
• Reduced clipping into chain shapes by fast bodies
• Friction and restitution are now remixed in the contact solver every time step
• Body move events are now correctly adjusted for time of impact

Infrastructure

• Unit test for API coverage
• macOS and Windows samples built in GitHub actions
• CMake install
• imgui and glfw versions are now pinned in FetchContent
• Initial Emscripten support