how to calculate L-section, cross section and depth from the 3d models of uav images
In Pix4Dmapper you can generate outputs in different formats such as point cloud, 3D mesh, DSM, orthomosaic, reflectance map. You can can even calculate surfaces, volumes of stockpiles and more. However, it is not yet possible to directly calculate L-section, cross section and depth.
You can possibly import the outputs generated by Pix4Dmapper to a third party software (AutoCAD) and perform your calculations there.