I started to CoDe this Grasshopper definition during my work experience at i-Mesh Architextile for an F+P collaboration.
It is very simple and maybe it will need some extra updates, anyway, it does what it promises. You can populate a surface with custom silhouettes (people or trees). Tweaking with sliders you will be able to obtain what you need during your parametric modelling session. I love the way to align silhouettes to your camera’s point-of-view
On my GitHub repo, you will find the GH User Object component and a Rhino 3DM file as shown in the video below.
Video demo of PopS v1 GH User Object component
Download this component from HERE