PlanetQuake ArghRad Tutorial: Aiming with Pitch and Yaw
Angle aiming in ArghRad uses two angle measurements to determine direction. The first is yaw, and the second is pitch. Yaw is the rotation horizontally. Everything that uses an angle key, such as doors, monsters, or player starts, uses the yaw value since the vertical rotation is not important. Yaw is measured from 0 (the positive x axis) to 360 (the same as 0) counterclockwise.
The second angle is the pitch. Pitch measures the angle up or down. A value of -90 will result in an aim pointing straight down (regardless of the yaw), and an angle of 90 will result in an aim pointing straight up.
An angle aimed at 180 -45 will be pointing toward the negative x axis (left, if viewed from above on the xy plane) and 45 degrees down.