Add ply doc

docs/getting_started.md

@@ -213,7 +213,29 @@ Examples:
 ```shell
 python demo/pcd_demo.py demo/kitti_000008.bin configs/second/hv_second_secfpn_6x8_80e_kitti-3d-car.py checkpoints/hv_second_secfpn_6x8_80e_kitti-3d-car_20200620_230238-393f000c.pth
 ```
+If you want to input a `ply` file, you can use the following function and convert it to `bin` format. Then you can use the converted `bin` file to generate demo.
+Note that you need to install pandas and plyfile before using this script. This function can also be used for data preprocessing for training ```ply data```.
+```python
+import numpy as np
+import pandas as pd
+from plyfile import PlyData
+
+def conver_ply(input_path, output_path):
+ plydata = PlyData.read(input_path) # read file
+ data = plydata.elements[0].data # read data
+ data_pd = pd.DataFrame(data) # convert to DataFrame
+ data_np = np.zeros(data_pd.shape, dtype=np.float) # initialize array to store data
+ property_names = data[0].dtype.names # read names of properties
+ for i, name in enumerate(
+ property_names): # read data by property
+ data_np[:, i] = data_pd[name]
+ data_np.astype(np.float32).tofile(output_path)
+```
+Examples:
 
+```shell
+convert_ply('./test.ply', './test.bin')
+```
 
 ### High-level APIs for testing point clouds