newton.geometry.build_ccd_generic#

newton.geometry.build_ccd_generic(support_func)[source]#

Build a continuous collision detection (CCD) system using a generic support function.

This function takes a support function as input and returns a collection of helper functions for performing collision detection between geometric primitives. The support function is used to find the furthest point on a geometry in a given direction.

The support function must have the following signature:

def support_func(geom: Any, geom_type: int, dir: wp.vec3) -> tuple[int, wp.vec3]:

The type of geom must be a struct that can look as follows:

@wp.struct
class Geom:
    pos: wp.vec3
    rot: wp.mat33
    normal: wp.vec3
    size: wp.vec3
    index: int

Note that only the index member is mandatory. All other members can be chosen as needed for the support function.

The returned functions implement the GJK (Gilbert-Johnson-Keerthi) and EPA (Expanding Polytope Algorithm) algorithms for computing distances between convex shapes and handling penetration cases.

Parameters:

support_func (Any) – A function that takes a geometry object, geometry type, and direction vector and returns (index, point) where: - index is the index of the support point in the geometry - point is the furthest point on the geometry in the given direction

Returns:

  • _attach_face: Attaches a triangular face to the polytope

  • _epa_support: Computes support points for EPA algorithm

  • _linear_combine: Performs linear combination of vertices

  • _almost_equal: Checks if two vectors are approximately equal

  • _subdistance: Computes closest point on simplex to origin

And other internal functions used by GJK/EPA algorithms.

Return type:

A collection of helper functions including

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