The speed at which 3D visualization can be done varies depending on the complexity of the project, the software used, and the expertise of the designer. Simple 3D models can be created in a few hours or days, while more complex visualizations, like detailed architectural renderings or interactive virtual tours, may take several days to weeks. Advanced projects that require high levels of detail, realism, or animation might take even longer. Efficient workflows and powerful software can speed up the process, but the quality and detail required will always influence the overall timeline.