Half-Life 2 Game Adding Precipitation tutorial

In this tutorial, you will use brush based entities to add precipitation to your map, either rain, snow, or falling ash. This is a relatively simple process, but this tutorial assumes intermediate skill in Hammer.

Create a basic map of any size.

Using brushes, create a simple structure in the center of the map. This will be a shelter from the precipitation.

Next, create a brush textured with “tools/toolsinvisible” covering the entire top half of the map, stopping at the roof of the structure. (A skybox wall in the picture is cut away)

Using the clip tool, section off the brush and drag the portions down so that the invisible brush covers the entire map, except for underneath the structure.



It may look awkward, but it’s ok if the brushes overlap a bit.

Control+click to select all of the invisible brushes and tie them (control+T) to a func_precipitation entity.

They will now become boxes in which the precipitation will fall. It’s important to note that the precipitation will not fall FROM the boxes, it will fall IN the boxes. Select which kind of precipitation you want under the “Precipitation Type” box.

With all of the brushes still selected, make them hollow with Control+H and enter 2 as how thick you want the walls. Remember, it’s ok if they overlap.

Add an “info_player_start” and test the map.

If you’re doing snow or ash, you’re finished. If you’re doing rain, you’re almost done. The last thing to do is add an ambient sound, because it looks a bit strange to see rain and not hear it.

Create an “ambient_generic” somewhere on the map. Name it “RainSound”, and select the “Play Everywhere” flag. All other flags should be unchecked. You also have to set the “Sound Name” property. I like ambient/levels/canals/dam_water_loop2.wav for heavy rain, but you can choose a different sound if you want.

You’re done! Precipitation is a great mood setter when used sparingly. I’d recommend using an “env_fog_controller” for heavy rain to make it look a bit better.

For questions or feedback, you can email (hambandito@gmail.com) or PM me.