It is important for companies that their operational employees have profound knowledge of the processes in which their work is embedded. 3D virtual world (VW) environments are promising for learning, especially for complex processes that have deviations from the standard flow. We design a 3D VW process training environment to improve process learning, particularly for complex processes with alternative flows, represented with gateways in process models. We adopt the method of loci, which suggests the mental traversal of routines for improving learning. Our experiment with 145 participants compares the level of knowledge acquired for a sample process with our 3D VW environment and a 2D depiction. We found that the 3D VW environment significantly increases the level of process knowledge acquired across the typical gateways in processes. Our results contribute to our understanding of how individuals learn knowledge of processes via 3D environments. With a low initial investment, practitioners are encouraged to invest in 3D training systems for processes, since these can be set up once and reused multiple times for various employees.