Structure from motion or stereoscopy are used to obtain 3D from a sequence of still images. However if there is no texture or features in the images, no 3D can be obtained. Featureless environments are difficult to reconstruct in 3D only using cameras. Projected light patterns can be used to measure the shape or an object. However, scattering is the main problem in light based underwater sensors such as light and cameras. Collimated light such as laser minimizes this problems by focusing the light in fewer points.