fix minor mistake

RefRef.py

@@ -76,6 +76,7 @@ class RefRef(datasets.GeneratorBasedBuilder):
                 gen_kwargs={
                     "filepaths": os.path.join(f"https://huggingface.co/datasets/yinyue27/RefRef/resolve/main/image_data/{cat}/{self.config.name}/",
                                               f"{self.config.scene}_sphere" if cat == "textured_sphere_scene" else self.config.scene),
+                    split: f"{'cubeBg' if cat == 'textured_cube_scene' else 'sphereBg' if cat == 'textured_sphere_scene' else 'envMapBg'}_{'singleMatConvex' if cat == 'single-convex' else 'singleMatNonConvex' if cat == 'single-non-convex' else 'multiMatNonConvex'}_{self.config.scene}",
                 },
             ) for cat in ["textured_sphere_scene", "textured_cube_scene", "environment_map_scene"]
         ]