Add 'within' function to SceneBox (#2991)

Co-authored-by: Matias Turkulainen <30566358+maturk@users.noreply.github.com>

nerfstudio/data/scene_box.py

@@ -34,6 +34,10 @@ class SceneBox:
     aabb[0] is the minimum (x,y,z) point.
     aabb[1] is the maximum (x,y,z) point."""
 
+    def within(self, pts: Float[Tensor, "n 3"]):
+        """Returns a boolean mask indicating whether each point is within the box."""
+        return torch.all(pts > self.aabb[0], dim=-1) & torch.all(pts < self.aabb[1], dim=-1)
+
     def get_diagonal_length(self):
         """Returns the longest diagonal length."""
         diff = self.aabb[1] - self.aabb[0]