How to load a textured mesh that can result in collision?

[zjwzcx]

I found two ways to load mesh into Isaac Gym:
1. self.gym.load_asset() -> self.gym.create_actor()
2. self.gym.add_triangle_mesh()

What's the difference between them?

I found that the mesh loaded by load_asset() shows the texture while it cannot result in correct collision. The mesh loaded by add_triangle_mesh() can result in collision but shows no texture.

Way 1:

        urdf_name = "xxxx.urdf"
        asset = self.gym.load_asset(self.sim, asset_root, urdf_name, asset_options)
        pose = gymapi.Transform()
        ahandle = self.gym.create_actor(env_handle, asset, pose, None, env_index, 0)

urdf file:

<?xml version="1.0" encoding="utf-8"?>
<robot name="statue" xmlns:xacro="http://www.ros.org/wiki/xacro">
 <link name="statue">
  <inertial>
   <mass value=".25"/>
   <origin rpy="0 0 0" xyz="0 0 0"/>
   <inertia ixx="1e-4" ixy="0" ixz="0" iyy="1e-4" iyz="0" izz="1e-4"/>
  </inertial>
  <visual>
   <origin rpy="0 0 0" xyz="0 0 0"/>
   <geometry>
    <mesh filename="obj_name.obj"/>
   </geometry>
  </visual>
  <collision>
   <origin rpy="0 0 0" xyz="0 0 0"/>
   <geometry>
    <mesh filename="obj_name.obj"/>
   </geometry>
  </collision>
 </link>
</robot>

Way 2:

        mesh = o3d.io.read_triangle_mesh('obj_name.obj')
        mesh_vertices = np.asarray(mesh.vertices).astype(np.float32)
        mesh_triangles = np.asarray(mesh.triangles).astype(np.uint32)

        tm_params = gymapi.TriangleMeshParams()
        tm_params.nb_vertices = mesh_vertices.shape[0]
        tm_params.nb_triangles = mesh_triangles.shape[0]
        self.gym.add_triangle_mesh(self.sim, mesh_vertices.flatten(order='C'),
                                    mesh_triangles.flatten(order='C'),
                                    tm_params)