novaphy.geometry

Collision shapes, broadphase modes, collision-pipeline entry points, and contact buffers. Core symbols are available at the top level of novaphy; the importable novaphy.geometry module also provides compatibility aliases and HydroelasticSDF.

import novaphy

shape = novaphy.CollisionShape.make_box(half_extents, body_index)
pipeline = novaphy.CollisionPipeline(model, broad_phase="sap")
contacts = pipeline.contacts()
pipeline.collide(state, contacts)

Pipeline Overview

A whole-model collision pass flows through the explicit pipeline:

Model shapes + SimState
        │
        ▼
CollisionPipeline.collide(state, contacts)
        │
        ├── broadphase candidates
        ├── narrowphase contact generation
        ▼
Contacts.rigid_contact_* / Contacts.soft_contact_*

• CollisionShape describes a shape, material, flags, local pose, and owning body/link.
• BroadPhaseMode selects "explicit", "nxn" / "all_pairs", or "sap" candidate generation.
• CollisionPipeline owns the collision options and allocates contact storage sized for the bound model.
• Contacts exposes rigid contacts as rigid_contact_* columns and particle / soft-point contacts as soft_contact_* columns.

Most solvers do not run collision internally. Call pipeline.collide(state, contacts) before solver.step(...) whenever those solvers should consume contacts. SolverIPC is the exception: libuipc runs its own collision handling and ignores the NovaPhy Contacts argument.

Shapes and Bounds

Class	Description
AABB	Axis-aligned bounding box.
CollisionShape	Collision shape descriptor.
HydroelasticSdfConfig	Validated runtime configuration consumed by CollisionPipeline.
Mesh	Triangle mesh wrapper.
HydroelasticSDF	Compatibility namespace whose nested Config dataclass only stores hydroelastic SDF option values.
ShapeConfig	Shape parameters used by builder helpers.
ShapeFlags	Shape visibility and collision bit flags.
ShapeType	Shape type enumeration.

For hydroelastic SDF collision, pass the executable top-level HydroelasticSdfConfig to CollisionPipeline. novaphy.geometry.HydroelasticSDF.Config is a compatibility value container and is not the pipeline's runtime config type.

Collision Pipeline

Class	Description
BroadPhaseMode	Broadphase mode enum.
BroadPhasePair	Candidate overlap pair from exposed SAP broadphase utilities.
CollisionFilterPair	Disabled shape pair entry.
CollisionPipeline	Configurable broad + narrow phase pipeline.
SweepAndPrune	Standalone Sweep-and-Prune broadphase utility.

Contact Data

Class	Description
Contacts	Structure-of-arrays contact aggregate consumed by solvers.

Hydroelastic SDF Tables

Hydroelastic SDF contact generation uses marching-cubes lookup tables in novaphy/src/collision/cuda/collision_cuda_hydro_mc_tables.cuh. The file is a shared source for both backends: CUDA compiles the arrays as device constant memory, while the CPU collision path includes the same header with the CUDA qualifiers disabled. This keeps CPU/CUDA hydro surface extraction on the same case table.

The table contents are generated from the standard 256-case marching-cubes triangulation table and flattened into:

• kHydroMcTriRange: prefix offsets for each cube case.
• kHydroMcFlatEdgeVerts: ordered edge endpoint pairs for all emitted triangles.
• kHydroMcCornerOffsets: the cube-corner order used by both CPU and CUDA code, with x/y/z stored in bit order.

When updating the tables, regenerate the full table from the same 256-case source instead of hand-editing individual cases. Keep the corner order and edge endpoint convention unchanged, update the count constants, and run the hydroelastic contract tests on both CPU and CUDA-capable builds:

python -m pytest python/tests/test_newton_hydroelastic_contacts.py -q -k "hydroelastic_sdf or generated_hydro_sdf or complex_pairs"
python -m pytest python/tests/test_collision.py -q

Functions

Function	Description
compute_inertia_mesh()	Newton-aligned solid-mesh inertia integrator.

Compatibility Notes

The following Newton-side newton.geometry APIs are not yet provided by NovaPhy:

• Per-pair narrowphase functions (collide_box_box, collide_sphere_sphere, collide_capsule_*, etc.)
• BroadPhaseAllPairs, BroadPhaseExplicit
• Public NarrowPhase class and top-level collide_shapes()
• Per-contact Python object classes such as ContactPoint / ContactManifold
• Analytical SDF helper functions (sdf_box, sdf_sphere, etc.)
• BVH builders (build_bvh_shape/particle, refit_bvh_shape/particle)
• compute_inertia_shape (general), compute_offset_mesh, transform_inertia
• MATCH_BROKEN, MATCH_NOT_FOUND constants