Menu: Edit / Simplify
Point cloud simplification will reduce the number of points in the point cloud, therefore creating a simplified version of the project.
This function works by retaining only one point per cube of a specified "grid size". The smaller the "grid size" value, the more points will be included in the simplified project; the larger the "grid size" value, the less points will be included.
You have to name the new project as well as select the project location. The project location may be set by clicking on the 
button. When ready, click on "start" to begin the simplification. The result of this function will be a new project that will be created in the specified project location.
