Using GPGPU, we developed a method to calculate the solid angle of landscape elements with an omnidirectional field of vision, via intersection detection. We confirmed that the processing speed was approximately 500 times faster than the processing speed achieved using a single CPU. Furthermore, the developed method was applied for the calculation of the omnidirectional green visibility of models with randomly arranged trees. Thus, the relationship between the shape and number of trees and the omnidirectional green visibility was analyzed statistically. These results can be considered as an index of the green visibility rate when planning the arrangement of trees.