Shading of PV panels by any obstruction will reduce the output of any panel.
Fundamentally a PV cell produces ~ 0.5 VDC. Amperage comes from the area of the cell and the amount of light the cell can "capture". Therefore, the fewer photons the cell can capture the less power it will produce since voltage is a constant.
The combination of series and parallel circuits on a single panel will determine how well it handles partial shading. However, you need to keep the voltage up to maximize efficiency of your solar system. It is a balancing act the panel manufacturers have to do. You can also wire your panels in the series/parallel combination to do the same thing.
2020 Rockwood Roo 19
2012 F150 SuperCrew Ecoboost