No instant_pred results for scans_test split (not val and without label) dataset ？

[small-zeng]

When I test scans_test split dataset (not val and without label) dataset,

python visualization.py --prediction_path ../results/ --room_name scene0707_00 --task instant_pred --out ../results/scene0707_00_instant_pred.ply

output is

but
python visualization.py --prediction_path ../results/ --room_name scene0707_00 --task semantic_pred --out ../results/scene0707_00_semantic_pred.ply

output is

Why instant_pred is missing?

[small-zeng]

python visualization.py --prediction_path ../results/ --room_name scene0707_00 --task instance_pred --out ../results/scene0707_00_instance_pred.ply is OK,