Manufacturing simulation is important to build understanding of a process. It is especially useful for learning about AM processes that are time consuming, expensive, and may have an environmental impact. Generating or modifying explicit meshed geometry during a simulation can be a computationally expensive task. Other geometric representations, such as implicit surfaces, make these types of topographical transformations easier and may be more suited to making as-manufactured models from simulations. Here, it is shown that signed distance fields are a flexible and efficient representation format for AM process simulation. The suitability of ray marching for the visualisation of these geometries is also shown. These simulation techniques enable quick feedback from design or process plan modifications to geometric model validation.