How to add 3D model object in 3Doccupancy map?

Question

I have created a 3D occupancy map to model a region where I want to test some path planning algorithms for an autonomous robot. I have created a 3D map along with obstacles, but my requirement is to add 3D model (eg, human,car,tree etc anything) to my map.

The example is difficult to understand. Can somebody help me in adding some model.

Note: I have made these buildings but i want to add some sort of models (like humans, tree,car etc) Also can we add png,or gif to our map? GIF of a Car

My 3D map

I have created a 3D map along with obstacles, but my requirement is to add 3D model (eg, human,car,tree etc anything) to my map.