topic Creating 3d Polygons from a 2d Shapefile for use with the Skyline Tool in 3D Questions

Creating 3d Polygons from a 2d Shapefile for use with the Skyline Tool

JonathanGillespie — Wed, 14 Aug 2013 19:18:57 GMT

Hi Folks

I would like to use the Skyline tool to determine the visible sky around several observation points. The objects blocking the view, as it were, are buildings obtained from a shapefile from LIDAR data. The building data is a 2d shapefile with an attribute for height. I've tried using the "feature to 3d by attribute" in the 3d analyst toolbox, but this seems to raise the 2d polygon to the height specified in the attribute rather than create a building shaped polygon. I've can view the buildings in 3d in ArcScene using the "Extrusion" tab but when the skyline tool is applied to this layer it gives a perfect circle around each point suggesting this is not working as intended. There is no base layer required for the purpose of this work although I have a digital elevation raster if it's required.

My question is - how do I make the skyline function work with my shapefile?

Thanks in advance.

p.s. apologies if this is answered elsewhere - I've been searching for a while with no success.

p.p.s I'm pretty inexperienced so if possible a simpler explanation would be good 😛

Re: Creating 3d Polygons from a 2d Shapefile for use with the Skyline Tool

EricRice — Thu, 15 Aug 2013 16:15:31 GMT

Extrude the polygons in ArcScene, then run Layer 3D to Feature Class to create a multipatch feature class which can be your Input Features in Skyline.

Best,
Eric

Re: Creating 3d Polygons from a 2d Shapefile for use with the Skyline Tool

JonathanGillespie — Thu, 15 Aug 2013 17:14:04 GMT

Extrude the polygons in ArcScene, then run Layer 3D to Feature Class to create a multipatch feature class which can be your Input Features in Skyline.

Best,
Eric

Hi Eric

Thanks for taking the time to reply. I've managed to create the multipatch feature as you instructed and once I realised I had to convert my points into 3d as well the skyline feature worked.

I've been trialing this on a small subset of the data so with a bit of luck it will work on the full set.

Thanks for your help.

Jonathan

Re: Creating 3d Polygons from a 2d Shapefile for use with the Skyline Tool

JonathanGillespie — Tue, 20 Aug 2013 07:58:50 GMT

Extrude the polygons in ArcScene, then run Layer 3D to Feature Class to create a multipatch feature class which can be your Input Features in Skyline.

Best,
Eric

Hi Eric

First of all, thanks for your help so far. I was planning to use the skyline tool to calculate the portion of sky visible from a series of observer points (around 65 in total at the moment). I originally thought I might be able to do this using the Skyline graph tool however it only reports a single value when run, regardless of the number of points in the input file. Is there any way to run this tool on multiple points to obtain a value for each point rather than a singe value for all points (which is what I assume it's calculating)?

Thanks in advance.

Jonathan

p.s. If you would prefer I start a new thread that's fine.