Cast shadow analysis

Aquasoli

I am currently wondering about the analysis of cast shadows based on the the terrain.

My background is, that I am trying to simulate the near shading effects by trees, buildings and other elevated objects onto lower terrain to see if the terrain behind / below will be shaded during specific hours of the day.

I figured out, that the shaded relief function allows for setting of different sun angles and azimuth and so I tried to work with this. However, it appears to me, that this functionality will only display, whether or not a specific area would in theory receive direct sunlight but it does not cast / show the shadow, which an object will throw.

So for example, I am attaching a view from a 3D model, where I overlaid three hill shading options. The model is located in Yamagata, Japan.

Option 1 (10:00 am)
Sun angle 24.5°
Azimuth 155°

Option 2 (12:00 pm)
Sun angle 28.5°
Azimuth 180°

Option 3 (14:00 pm)
Sun angle 20°
Azimuth 215°

I am aware, that the above numbers are not 100% correct, but it is accurate enough for my purposes.

My point is, that the programm just creates dark areas, where there is no direct sunlight, but it does not cast shadows. In this case, there are two buildings in the centers, which are roughly 30m and 40m high and they would probably cast quite far shadows behind them.

Is there a way to do this? I would like to see, how far shadow is reaching but right now it seems that the programm is not doing that.

Regards,

Jakob

bmg_mike

Hi Jakob,

The just release Global Mapper 26.0 has a new solar/shadow calculation module allowing you to calculate real shadows based on sun position (given date/time and location) using loaded terrain and 3D areas and meshes.

Thanks,

Mike

Global Mapper Guru