Sun Shadow Frequency - General questions

Question

Hello!
I am using ArcGIS Pro 3.1.1 and was trying to use the Sun Shadow Frequency tool.

I had no idea what the correct parameters were, so I just chose my features and then run the simulation, set with the current time. Now I have the map with two colors, 0 and 1. Does this mean now that all areas with 1 are in the shadow and the ones with 0 are without (at least that's what makes the most sence to me)?

What I originally wanted to do is creating a layer that shows me the shadows of my buildings during a whole (summer) day. But everytime I try to run the task with setting a start and an end time, I only get a layer with only one color (and no shadows?)...

Can someone please help me and tell me

1. What exactly is the output of the tool?

2. what parameters do I have to put there to get a sucessful simulation?

Thanks alot!

Remi_Foicik · Answer

Hello Andressa,

The inputs features class for this tool must be "multipatch"

You can transform 3d features to multipatch feature class with the geoprocessing tool:
Layer 3D To Feature Class (Couche 3D vers classe d’entités) : ArcGIS Pro | Documentation

Or you can also transform it in City Engine or apply a city engine rule in ArcGIS pro with (if you have the licence) :
Entités des règles CityEngine (3D Analyst) : ArcGIS Pro | Documentation

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AndressaMuraro · Answer

Hello community!

I'm trying to use the tool, but the Input Features already returns an error.

My features are polygons and I've already made sure it's a Feature Layer. I tried Polygon Z, Polygon and Polygon ZM, none of them worked. What am I doing wrong?

Remi_Foicik · Answer

Hi !

You can add multiple inputs in the geoprocessing tool as long as they're multipatch feature class.

But the more objects, the longer the calculation time....so it will be a problem for you apparently.

I checked the tool and unfortunately, it's not very well optimized. Sun shadows frequency can't use GPU and it can only use mono-thread CPU calculation power.

What I did was segmented my input datas and I launched several instances of the tool at the same time.

For example, if you want to make a simulation for a whole day, you can launch several instances of ArcGIS Pro as your CPU and RAM allows (or by script, it was what I did) and start the geoprocessing tool with different time interval (00:00-01:00; 01:00-02:00; 02:00-03:00;....)

If you lauch the tool on a whole day of summer per hour, you can (virtually, depending of you computer) divide the time it will take by 15 😉

After that, you can do a simple raster calculation at the end with all ouptut rasters.

Hope it could help !

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