This study is a prospective observational study designed to evaluate the effectiveness of Brainlab's Mixed Reality Viewer in enhancing the accuracy and efficiency of preoperative craniotomy planning. The study will be conducted at a single site with two enrollment groups. Group 1 has a target enrollment of 38 subjects. Group 2 has a target enrollment of 16 subjects. By observing the device's use during standard surgical procedures, we can accurately measure its impact on incision planning accuracy, time efficiency, and overall ease of use compared to traditional neuronavigation systems. This design allows for the collection of both quantitative and qualitative data, providing a robust assessment of the Mixed Reality Viewer's potential to enhance surgical outcome