An optimized velocity model is an important step towards the goal of accurate and precise seismic results. The assumption of a single or layered velocity model is not always appropriate in examples such as rock volumes that contain complex shaped geological units or large voids. For this reason, this study presents a 3D velocity model method that can be used for source location and source mechanism analysis. Examples from two case studies are presented with the first being an open stope mine, and the second being a block cave mine with 5 geological domains. Using calibration blast data, a significant improvement is shown when the excavation stopes are accounted for in the location velocity model. It is also shown that accounting for the shapes of different geological domains and cave voids produce more accurate raypaths for the seismic energy than from using a single velocity model and straight raypath assumption. This improvement in accuracy is benefiting the integration of seismic results with numerical models and the overall effort to improve the safety and productivity in the rock mechanics industry.