Perception using stereo requires external light. In the absence of natural light, active, structured light provides light where it is needed. In this work, we demonstrate how a free moving line striping laser can be used to perceive and model terrains. In this formulation, we do not need to know the position of the laser with respect to the stereo pair which precludes the need for calibrating the laser position. This also saves an actuator as the laser can be passively articulated using a spring. In this paper, we present the algorithms to efficiently extract the laser pixels from the stereo image pair. We also present techniques to use the structure of the light and overcome degenerate cases to build cleaner maps. This perception method benefits micro-rovers specifically those trying to operate in the extreme lighting conditions.