{
  "multipart": [
    { "when": { "OR": [
        { "up": "true" },
        { "north": "low", "east": "low", "south": "low", "west": "low" },
        { "north": "tall", "east": "tall", "south": "tall", "west": "tall" }
      ]},
      "apply": { "model": "minecraft:block/polished_blackstone_wall_post" }
    },
    { "when": { "north": "low" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side" }
    },
    { "when": { "east": "low" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side", "y": 90 }
    },
    { "when": { "south": "low" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side", "y": 180 }
    },
    { "when": { "west": "low" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side", "y": 270 }
    },
    { "when": { "north": "tall" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side_tall" }
    },
    { "when": { "east": "tall" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side_tall", "y": 90 }
    },
    { "when": { "south": "tall" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side_tall", "y": 180 }
    },
    { "when": { "west": "tall" },
      "apply": { "model": "minecraft:block/polished_blackstone_wall_side_tall", "y": 270 }
    }
  ]
}