Additive Manufacturing processes such as laser metal deposition (LMD) are often used in repairing processes where material is deposited onto existing components. During the LMD process, thermal stresses and deformations of the substrate can occur. This deformation results from a multitude of effects throughout the manufacturing process. To precisely measure the time-temperature-deformation history, an experimental setup combining in situ deformation measurement and thermography is conceived. 3D deformations are measured using a stereo camera system observing a stochastically distributed speckle pattern applied on the surface of the substrate. Additionally, the temperature is measured on the underside of the substrate by means of thermal camera. Material is applied using LMD on the opposite side of the measurement therefore there is no chance of the laser beam interfering with the optical measurement of temperature and deformation or damaging the measurement equipment. Due to the areal nature of the measurement system chosen, it is possible to achieve high temporal and spatial resolution to identify critical heat distributions and welding path strategies, which lead to deformation. This work proposes a novel measurement setup and provides possible use cases for optimizing path planning during additive manufacturing processes based on three exemplary path geometries.