How to create a collision object from a (convex) mesh

[manuel-koch]

I'm new to hpp-fcl and can't find useful documentation about the python interface.
There seem to be some c++ code examples ( mostly doxygen stuff ) but I have difficulties converting them to python.

I'm trying to replicate some functionality from the original fcl library.
In their example they have something like

# FCL for a non-convex mesh
verts = np.array([[1.0, 1.0, 1.0],
                  [2.0, 1.0, 1.0],
                  [1.0, 2.0, 1.0],
                  [1.0, 1.0, 2.0]])
tris  = np.array([[0,2,1],
                  [0,3,2],
                  [0,1,3],
                  [1,2,3]])
m = fcl.BVHModel()
m.beginModel(len(verts), len(tris))
m.addSubModel(verts, tris)
m.endModel()

# FCL for a convex mesh
verts = np.array([[1.0, 1.0, 1.0],
                  [2.0, 1.0, 1.0],
                  [1.0, 2.0, 1.0],
                  [1.0, 1.0, 2.0]])
tris  = np.array([[0,2,1],
                  [0,3,2],
                  [0,1,3],
                  [1,2,3]])
faces = np.concatenate((3 * np.ones((len(tris), 1), dtype=np.int64), tris), axis=1).flatten()
c = fcl.Convex(verts, len(tris), faces)

# how would it look like for HPP-FCL ??

How would that look like for hpp-fcl ?
Thank you for helping getting starting with hpp-fcl.

[manuel-koch]

I tried this, but it crashes

import hppfcl as fcl

mesh = Trimesh(
    vertices=extended_3d_data.vertices,
    faces=extended_3d_data.faces,
)
if mesh.is_convex:
    fs = numpy.concatenate(
        (3 * numpy.ones((len(mesh.faces), 1), dtype=numpy.int64), mesh.faces), axis=1
    )
    return fcl.Convex(mesh.vertices, len(fs), fs.flatten())
else:
    bvh = fcl.BVHModelOBB()
    bvh.beginModel(len(mesh.faces), len(mesh.vertices))
    bvh.addSubModel(
        verts=numpy.array(mesh.vertices),
        triangles=numpy.array(mesh.faces),
    )
    bvh.endModel()
    return bvh

>           bvh.addSubModel(
                verts=numpy.array(mesh.vertices),
                triangles=numpy.array(mesh.faces),
            )
E           Boost.Python.ArgumentError: Python argument types in
E               BVHModelBase.addSubModel(BVHModelOBB)
E           did not match C++ signature:
E               addSubModel(hpp::fcl::BVHModelBase {lvalue}, std::__1::vector<Eigen::Matrix<double, 3, 1, 0, 3, 1>, std::__1::allocator<Eigen::Matrix<double, 3, 1, 0, 3, 1>>>)
E               addSubModel(hpp::fcl::BVHModelBase {lvalue}, std::__1::vector<Eigen::Matrix<double, 3, 1, 0, 3, 1>, std::__1::allocator<Eigen::Matrix<double, 3, 1, 0, 3, 1>>>, std::__1::vector<hpp::fcl::Triangle, std::__1::allocator<hpp::fcl::Triangle>>)

../poc_runner/collision_detection/hpp_fcl.py:134: ArgumentError

[manuel-koch]

Mentioned in ticket #423