void Update()
        {
            var mesh    = target.sharedMesh;
            var posList = mesh.vertices
                          .Select(vtx => target.transform.TransformPoint(vtx))
                          .ToList();

            TargetCameraUtility.Update(camera_, posList);
        }
        void UpdateCamera()
        {
            var pair      = parentGate.pair;
            var pairTrans = pair.transform;
            var mesh      = pair.GetComponent <MeshFilter>().sharedMesh;
            var vtxList   = mesh.vertices.Select(vtx => pairTrans.TransformPoint(vtx)).ToList();

            TargetCameraUtility.Update(camera_, vtxList);

            // Oblique
            // pairGateの奥しか描画しない = nearClipPlane を pairGateと一致させる
            var pairGateTrans = parentGate.pair.transform;
            var clipPlane     = CalcPlane(camera_, pairGateTrans.position, -pairGateTrans.forward);

            camera_.projectionMatrix = camera_.CalculateObliqueMatrix(clipPlane);
        }