Drag the water jet in the material library to the placement area. Use the left mouse button to drag and move the water jet. Press the C key and drag the small square on the model with the mouse to change the size;

1. Left-click to select the water jet. Press and hold the left mouse button and drag the small square around the water jet to modify the size. (Note: Dragging the small squares at the four corners modifies proportionally, and dragging the small square in the middle modifies in one direction.)

2. Precise modification of the water jet size:

Select the value and re-enter the value to modify the size.