Issue with the fog simulation code which is "attributeerror: Can't get attribute '_map' on <module '__mp_main__' "

[AIsimrand]

Hello Author,

I am working on generating synthetic data using your Lidar fog simulator on Kitti velodyne data. but somehow I am getting this particular error "attributeerror: Can't get attribute 'map_test' on <module 'mp_main' " which I am unable to resolve or understand.
If you could just let me know any changes I need to do in the particular code would be great help for me.
Looking forward for your reply.
Thank you in advance

[MartinHahner]

Are you using Windows? It might be related to that.

[MartinHahner]

Try changing n_features to 4. KITTI might not have the channel encoded in the point cloud and only contains 4 features (x,y,z,i).

LiDAR_fog_sim/fog_simulation.py

Line 28 in 61b721b

parser.add_argument('-f', '--n_features', help='number of point features', type=int, default=5)

[AIsimrand]

Thank you Author,
the code runs fine now.
just 1 more question why is the fog_simulation code saving multiple velodyne_CVL_beta folder consisting of similar bin files?

[MartinHahner]

I am sorry, I don't know what you are talking about. Please be more specific.

[AIsimrand]

Yeah ,
well I am trying to run the fog_simulation.py script so its saving multiple folders that consist of .bin files.
folders are named like velodyne_CVL_beta_0.005 , velodyne_CVL_beta_0.010 and so on.
So i just want to know that what is available_alpha as it's value keeps increasing and as per that it saves augmented fog ?

[MartinHahner]

Alpha ranges from 0.005 to 0.2, the values are taken from the files located here:
https://github.com/MartinHahner/LiDAR_fog_sim/tree/main/integral_lookup_tables/original

LiDAR_fog_sim/fog_simulation.py

Lines 37 to 49 in 61b721b

	def get_available_alphas() -> List[float]:
	alphas = []
	for file in os.listdir(INTEGRAL_PATH):
	if file.endswith(".pickle"):
	alpha = file.split('_')[-1].replace('.pickle', '')
	alphas.append(float(alpha))
	return sorted(alphas)

The resulting bin files are the augmented point clouds containing different levels of fog.
The higher alpha/beta, the denser the fog.

Please make sure to read and understand the paper before asking more questions. Thank you.