def create_cloth(self, builder):
      builder.add_cloth_grid(
          pos=wp.vec3(0.0, 0.0, 0.0),
          vel=wp.vec3(0.1, 0.1, 0.0),
          rot=wp.quat_from_axis_angle(wp.vec3(1.0, 0.0, 0.0), -math.pi * 0.25),
          dim_x=dim_x,
          dim_y=dim_y,
          cell_x=1.0 / dim_x,
          cell_y=1.0 / dim_y,
          mass=1.0,
          tri_ke=10000.0,
          tri_ka=10000.0,
          tri_kd=100.0,
          tri_lift=10.0,
          tri_drag=5.0,
      )

  def create_builder(self):
      builder = self.create_modelbuilder()
      env_builder = self.create_modelbuilder()
      self.create_cloth(env_builder)
      self.env_offsets = compute_env_offsets(self.num_envs, self.env_offset, self.env_offset_correction, self.up_axis)
      for i in range(self.num_envs):
          xform = wp.transform(self.env_offsets[i], wp.quat_identity())
          builder.add_builder(
              env_builder,
              xform,
              update_num_env_count=True,
              separate_collision_group=self.separate_collision_group_per_env,
          )
      return builder