Rendering:
1. Open a photo, then create a new layer, and while holding down the ALT key, use the mouse to click the Add Mask button at the bottom of the layer panel to add a black mask to layer 1.
2. Select the mask with the mouse, execute Filter - Pixelate - Dotted in the mask state, and set the cell size to 3.
3. Then execute Image-Adjustment-Threshold on the mask and set the threshold level to about 185.
4. Next, execute Filter-Blur-Motion Blur, set the angle to -45, and the distance to about 20.
5. Execute CTRL+L on the mask to open the level adjustment panel. In the layer 1 mask state, set the input level to 22, 1.34, and 129. By changing this parameter, you can adjust the size of the raindrops in the photo.