Selective Laser Melting (SLM) is a 3D printing technology which is suited for additively manufacturing of metals and polymers. The main barriers of this process are the lack of reproducibility and the control of the influence of the process parameters, like laser power, scan rate, layer height and particle distribution for instance. A high fidelity simulation scheme for SLM processes can not only give an insight into the physical behaviour during the process, but can also help to control the whole 3D printing process in order to guarantee the reproducibility of the desired final product properties. However many challenges have to be overcome in order to guarantee a high fidelity simulation, like modelling the heat source or the phase change for instance. In this work the modelling of the heat source is addressed. A Ray Tracing algorithm should be implemented into the existing thermomechanical Optimal Transportation Meshfree (OTM) code. A Ray Tracing algorithm for the simulation of laser processes is investigated in combination with the Discrete Element Method in the literature. Therefore in a first step this algorithm should be recoded in order to benchmark the implemented Ray Tracing algorithm. In the next step this algorithm has to be implemented into the OTM code. An investigation by means of some examples should demonstrate the influence of the Ray Tracing algorithm on the fusion of two metal particles.