Information visualization is widely involved in our daily life. It develops rapidly in both 2D and 3D environments. In the 3D case, evaluation is a critical problem. Existent evaluation metrics are firstly introduced in this paper. We chose to focus on mathematical metrics only and several metrics referring existent ones are designed to evaluate a text-based information visualization in 3D urban environment. Afterwards, some modifications of the visualization are gained by constructing processing functions which take into account the object space distance and the screen space distance. A re-evaluation process for the new results is conducted to see if the visualization result is improved or not. Results show that screen space functions have better performance in improving visualization performance, which can provide references for visualization designers to diversify and characterize their visualizations.