fix(studio): 尝试修复密度比找不到的 warning

src/Studio/Resource/Lattice.php

@@ -41,6 +41,8 @@ use Singularity\HDK\Utils\Resource\ClassicResponse;
  * @property string         $deletedAt
  *
  * @property array          $evaluation      性能评估
+ * @property array          $material
+ * @property mixed          $pivot
  */
 class Lattice extends JsonResource
 {
@@ -72,7 +74,7 @@ class Lattice extends JsonResource
             'a' => (float)$this->a,
             'b' => (float)$this->b,
             'c0' => (float)$this->c0,
-            'scalingRatio' => (float)$this->pivot->scaling_ratio,
+            'scalingRatio' => (float)$this->pivot?->scaling_ratio,
             'evaluation' => LatticeEvaluation::make($this->evaluation),
             'material' => Material::collection($this->material),
         ];