1. A robot controller comprising: a drawing section configured to perform first and second drawing processes; a collision detection section configured to detect that a collision detection target object collided with a first object; and a processor configured to perform as the drawing section and the collision detection section, wherein the first drawing process is based on depth map information of the collision detection target object so as to provide a first result, the second drawing process is not based on the depth map information of the collision detection target object so as to provide a second result, and the collision detection section detects whether the collision detection target object collided with the first object based on the first and second results and provides a first collision detection result.