Google Earth for visual impact (KML)

Situation at present:

At the moment, openwind will calculate zones of visual impact (ZVIs) or "viewsheds" based on various measures of visual impact.

It will also output animated turbine layouts to Google Earth as well as other raster, image and vector layers.

The ZVI algorithm will take into vegetation height input as a raster or polygon vector layer.

Problem:

Google Earth does not support polygon drawing with <tesselation> and <relativeToGround> and so we can't draw forestry blocks in GE (except on flat terrain) and therefore the ZVI will not match visual impact in Google Earth.

Bounty:

A family size bag of kudos goes to anyone who can suggest a practical way to get around this limitation in Google Earth. You don't even need to implement it (although a KML file which demonstrates the concept would be lovely). Just explain it in this thread and if it makes sense, we will attempt to implement it in openwind.

Previously nick wrote:

Hi Nick, loving the software. Just one quick question about the google earth animations. I have used a local projection for a site in Greece in m (HGRS87) and was wondering how I get this layout into the correct location in my GE. GE uses lat/long which is not a m grid as you prefer, at the moment my layout is in the sea...do you know any fancy work arounds for this?
Aaron

Hi Aaron,

Welcome to the forum. glad you're liking the software. Please don't hesitate to suggest improvements or submit bug reports.

I think the problem is that my software does not recognise your projection. It only recognises UTM projections. However, you're not the first person to have this problem (am currently trying to find out what the UK uses). Unfortunately, the Greek projection system you refer to is not a modified form of UTM and so I have no idea how to convert from it to Geographic and back. If you could direct me to this information I might be able to add it OpenWind. An alternative would be for you to convert your data using a GIS software such as ArcView before entering it into OpenWind. OpenWind only knows about cylindrical projections and is just now limited to UTM so although the models work just fine with teh data you input, you wont be able to use the Google Earth export or the GPS function unless you convert your data to UTM using a GIS or until I can add the appropriate projection info to OpenWind.

Also, please note that the turbines that OpenWind outputs are generic and their dimensions are not modified to match the ones you input into the turbine types. At present I'm trying to get the turbine manufacturers to supply models but suspect I'll end up paying someone to make some common variants. If you are prepared to modify the turbine model yourself, I can supply you with the DAE file and you can take it into Google Sketchup and make it fit the dimensions you want. I can then add your model to the library.

Cheers,

Nick

hi
my name is jose luis  mexican.
I really liked your progama,
But I would like you to tell me is to figure
to calculate ZIV.
what information I need.
to do the analysis.

thanks and greetings.

I think if you work through the tutorial, things will become clearer.

You need turbine spec, positions and terrain model as a minimum.

Nick