Question about overlap ratio in 3DMatch.pkl

[Shi-Qi-Li]

Hi authors,
Thank you for the amazing work!

I have a question about the overlap ratio in 3DMatch dataset. I load the .pkl files in configs/indoor, the overlap ratio of train_info/val_info/3DLoMatch dataset looks normal but the overlap ratio of 3DMatch is a little strange. I think the overlap ratio in 3DMatch should greater than 0.3, but I found half pairs have a overlap less than 0.3 and some pairs even less than 0.1. I'm really confused about it.

Here is my code to load pkl and print the overlap ratio.

import pickle
import numpy as np

def load_obj(path):
    """
    read a dictionary from a pickle file
    """
    with open(path, 'rb') as f:
        return pickle.load(f)
        

if __name__ == "__main__":
    base_path = "aa/bb/"
    
    train = load_obj(base_path + "OverlapPredator/configs/indoor/train_info.pkl")
    print("num in train", len(train["rot"]))
    print("overlap range in train", np.min(np.array(train["overlap"])), np.max(np.array(train["overlap"])))

    val = load_obj(base_path + "OverlapPredator/configs/indoor/val_info.pkl")
    print("num in val", len(val["rot"]))
    print("overlap range in val", np.min(np.array(val["overlap"])), np.max(np.array(val["overlap"])))

    match = load_obj(base_path + "OverlapPredator/configs/indoor/3DMatch.pkl")
    print("num in 3dmatch test", len(match["rot"]))
    print("overlap range in 3dmatch test", np.min(np.array(match["overlap"])), np.max(np.array(match["overlap"])))
    print("num overlap<0.1", np.sum(np.array(match["overlap"]) < 0.1), "num overlap<0.3", np.sum(np.array(match["overlap"]) < 0.3))

    lomatch = load_obj(base_path + "OverlapPredator/configs/indoor/3DLoMatch.pkl")
    print("num in 3dlomatch test", len(lomatch["rot"]))
    print("overlap range in 3dlomatch test", np.min(np.array(lomatch["overlap"])), np.max(np.array(lomatch["overlap"])))

Here is the output.

Thank you and look forward to your reply!