An electronic device and method are disclosed. The electronic device includes a first and second camera, display, memory and processor. The processor implements the method, including acquiring image data of an external environment via the first camera, detecting a plurality of objects included in the image data, identifying a first object corresponding to the detected gaze among the detected plurality of objects, configuring a first precision for spatial mapping of the identified first object and a second precision of at least one other object from among the detected plurality of objects, wherein the first precision is higher than the second precision, executing 3D spatial mapping on the image data using the first precision for the identified first object and the second precision for the at least one other object, and displaying a 3D space generated based on the image data and the spatial mapping.