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My company plan to investigate a 3D GIS system with unigine.But I studied it in little time.

So i want to know that can the unigine do it ? if can ,what must i study and pay attention to?

what i be making ready for? if not. please give a reason.

Thanks!

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one big advantage of UNIGINE compared to other game engines is double precision support which is mandatory for GIS applications supporting global scale data presentation. Nevertheless it's a game engine and GIS is a totally different field of application (especially in 3D). To be honest for hardcore GIS I would take some Java based approach based on existing GIS frameworks/libraries e.g. WorldWind.

 

Nevertheless UNIGINE can be used nicely for simple real-time 3D geographic data visualizations as shown in the following example

 

post-82-0-09699800-1337798989_thumb.jpg

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Yuwen, it's not quite clear what input data you have and in what format.

 

Ulf, thank you for sharing your opinion (very constructive since we hadn't created a GIS applications in the house) and even a screenshot :)

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We have done some work getting kml files into Unigine, with some sucess. Ill see if Danni can post more info on the tools we used.

 

Also we use Georeferenced satellite photography as the diffuse on terrains.

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We have done some work getting kml files into Unigine, with some sucess. Ill see if Danni can post more info on the tools we used.

 

Also we use Georeferenced satellite photography as the diffuse on terrains.

 

I must to achieve a 3D GIS demo with the Unigine. but i have nothing now. can you give me some advices?

Data source -->Process-->View. what are the three parts prepare for?

I think that i need to consult some sample code. where can i find it in?

Thanks!

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you have a few options...

1) you can try building a C++ plugin for unigine that integrates an existing gis library.

2) use the system uniginescript call to interact with external executables.

 

Basically we were doi ng the later we have latitude,longitude coordinates for the origin in our world file then we use an external program to convert other latitude,longitude coordinates into an offset from the origin using mercator mapping (IIRC). We were doing this to place buildings (whole models) and also to generate geometry on the fly.

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you have a few options...

1) you can try building a C++ plugin for unigine that integrates an existing gis library.

2) use the system uniginescript call to interact with external executables.

 

Basically we were doi ng the later we have latitude,longitude coordinates for the origin in our world file then we use an external program to convert other latitude,longitude coordinates into an offset from the origin using mercator mapping (IIRC). We were doing this to place buildings (whole models) and also to generate geometry on the fly.

 

Now i have nothing about 3D GIS map. i could not find the 3D GIS map in NET.

so i want to know where can download the 3D GIS map data of free(for Demo) in NET?

Can you save some pictures from your 3D GIS application to exhibit in this page?

or demo URL ?

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the internet is crowded with free GIS data (e.g. Blue Marble, SRTM, Natural Globe,....). If you already have problems gathering the source data than I would guess that it will be quite hard to do the data processing and visualization....

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Hi Denis, most probably www.naturalearthdata.com provided easiest access to consolidated global vector and raster height and image data. NASA BlueMarble dataset provides nice seasonal globe satellite imagery.

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Hi Denis, can I suggest another database that contains both height data (DEM) and satellite photo is http://asterweb.jpl.nasa.gov/gdem.asp They have recently released a new dataset global dataset ASTER GDEM version 2 with should provide height data to a resolution of 10m per pixel.

 

Hi Ulf, I couldnt find any reference to DEM raster data in the www.naturalearthdata.com dataset. There was reference to Shaded Relief but this appeared to be more of a terrain with a light shone on it to bring out the relief. I could be wrong?

 

A good tool for cutting tiles of GIS data and reprojecting it is GlobalMapper, it can also load and align many of the free datasets directly and has a lot of inbuilt data sources. In reality since Unigine is really setup for flat earth data, any data should be reprojected to flat projection rather that a curved one such as WGS 84.

 

I would be keen to discuss with Denis and Ulf, on any best methods for getting DEM and image data across to Unigine.

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Hi Ulf, I couldnt find any reference to DEM raster data in the www.naturalearthdata.com dataset. There was reference to Shaded Relief but this appeared to be more of a terrain with a light shone on it to bring out the relief. I could be wrong?

 

Don't think so, actually naturalearth only provides these preprocessed shaded reliefs. I just stumbled over this homepage while searching for some country border vector data and didn't spend too much time on screening all data. Nevertheless they provide some consolidated GIS data from different sources, which should be helpfull for most users (you can wast soooo much time on data preprocessing and conversion...)

 

 

I would be keen to discuss with Denis and Ulf, on any best methods for getting DEM and image data across to Unigine.

 

Steve, I think this is a general issue, not a Unigine specific one: how to get GIS data to a game engine ? From my point of view Ai3D is already doing it the way it should be done. GobalMapper seems to be a very good tool for data conversion and added Unigine support for PGM data format should have simplified data transformation. A common missunderstanding is that a lot of people mix general data transformation process with game engine data import issues.

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The GIS data is a highly complex matter ,Ai3D has already solve that how to get GIS data .

has your GIS data been made by yourself? or free download from NET? Could you explain it a little more.

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Free download from Internet is only possible from other country except China. In China, you know everything is kept as secret in government. for Example, in China of course you can get about 10 years old of 25m precision of DEM data. more precision DEM data is NOT FOR SALE, you can not get it. except you are one of some Related Department :D .

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Denis : It appears that Unigine is still suffering from small world problems. eg if i move the editor camera or player dummy camera out 200km and move an object there also, the camera is shaking quite a bit. I thought that "All objects are rendered in camera space". meant that the camera was at the world centre?

 

 

yuwen.xiang :

 

There is a lot of GIS data freely available online (maybe not in China) for example, roadmaps, coastlines. See Ulfs suggestion http://www.naturalearthdata.com/features/ or http://gdex.cr.usgs.gov/gdex/

 

Othertime we get more specific GIS data that is only available from our city council in .shp or .kml files. Im sure you can find free ones here somewhere http://wiki.openstreetmap.org/wiki/Shapefiles

 

We use Globalmapper to get our aerial photography and heightmap, shapefiles data aligned and mapped to the correct projection and grid. There are other applications if you want to hand paint your terrain.

 

Also read this post on Terrain https://developer.unigine.com/forum/topic/547-useful-terrain-tools/page__hl__terrain__fromsearch__1

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  • 3 weeks later...

Thanks ,now I study ossimplanet source code. so I want to make a c++ plugin for deal with 3D GIS data with ossimplanet part code. but i don't know it can? anyone do it???

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Could you please provide us some use cases for 3D GIS since we don't know what exactly is expected from "3D GIS support in Unigine"?

 

As far as I understand, the situation is the following:

* there is a number of formats for storing geodata (both vector and raster ones)

* geodata uses geographically-correct coordinate systems

* there is a number of geodata sources (maintained by special organizations)

* some custom geodata should be mixed to global database

* real-time 3D GIS application should visualize geo-mapped objects

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You are right.

 

I think the ability for Unigine to load, for instance, Geo Tiff digital elevation models to build terrain could be a plus for some users here (it's exactly what I'm looking into for my company project).

 

All informations about the terrain (dimensions, height, position) are in the Geo Tiff.

 

You could look at http://www.gdal.org/ for GIS formats reading and writing + tools

 

Anyway, the ability to have LOD and paged terrain in Unigine is already a great feature =)

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I had in troubled waters now. For example, i have one city map(DEM and DOM),and i want to add the city node coordinate data(*.shp or *.kmz).

Now how to load the DEM and DOM map file? And the vector file(shp)? how to relation and make a vectorgraph for view.

if i want to add the search function.how to do?

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Could you please provide us some use cases for 3D GIS since we don't know what exactly is expected from "3D GIS support in Unigine"?

 

As far as I understand, the situation is the following:

* there is a number of formats for storing geodata (both vector and raster ones)

* geodata uses geographically-correct coordinate systems

* there is a number of geodata sources (maintained by special organizations)

* some custom geodata should be mixed to global database

* real-time 3D GIS application should visualize geo-mapped objects

 

Denis, very good summary of the situation, but be sure this only scratches the surface of the problems to solve...

 

A simple answer for "3D GIS support in Unigine" would be "Rebuild Google Earth with Unigine"...already something I wouldn't really recommend....

 

A more detailed answer only on 3D GIS render implications and challenges can be found in the very good book "3D Engine Design for Virtual Globes" which - if I remember it right - is available in your private library.. have a short look, just 500 pages....

 

And finally a more detailed answer on GIS data formats, datums, projections, import, export, conversion, mergin, ...., ...., is a whole universe of its own.

 

To put it short: UNIGINE shouldn't try to put too much energy into this area

 

1) because it's a dammed complex topic and

2) most of the required data pre-processing etc. will be project specific anyway

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Now how to load the DEM and DOM map file? And the vector file(shp)? how to relation and make a vectorgraph for view.

if i want to add the search function.how to do?

 

Yuwen, I am quite sure that you will get fully lost when trying to convert complex shapefile geometry to UNIGINE mesh format..of course it's possible, but requires a lot of coding and detailed insight. Also game engines do no really support complex vector line rending well, so expect all kinds of upcoming trouble and frustration....

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* there is a number of formats for storing geodata (both vector and raster ones)

 

- Yes, common vector ones are shp , tab, and kml and even autocad(if you know what grid and projection it is using).

 

- Common raster files are ecw and geotiff, though any image format eg jpg can be used if accompanied by a locator file.

 

 

 

* geodata uses geographically-correct coordinate systems

 

Yes the data must have stored in the file or with an accompanying file, both the correct location in the coordinate system as well as which grid system. Grids are differenct projections, some maintain a curved earth system such as Google Earth which uses WGS84 while others are stretched flat, such as UTM.

 

I believe Unigine is currently better setup to handle a flat earth system such as UTM due to its existing coord system, the water and atmosphere systems.

 

 

* there is a number of geodata sources (maintained by special organizations)

 

Yes, and there is large amounts of free data.

* some custom geodata should be mixed to global database

 

Yes, a lot of GIS data is owned and is provided to us by Government or business and we must incorporate that as well. It is typically in the same formats as the global databases.

 

 

 

* real-time 3D GIS application should visualize geo-mapped objects

 

Ideally, if Unigine could import georeferenced heightmap data (in Geotiff) and georeferenced satellite imagery (in Geotiff) and then automatically tile it into its terrain system, and move it to the correct position (Unigine would need to decide which grid to use).

 

 

Here is a typical tutorial used by Google earth to import vector and raster data

http://www.google.co.../importgis.html

 

 

 

GIS data handling is a very complex area due to the different Grids and Projection systems, and the number of different formats available.

 

 

 

Perhaps the best starting point would be to get people to download and prepare their data, and convert it into a format that Unigine could deal with, eg Geotiffs and Shp files using a fixed grid/projection system. Then all Unigine would need and an importer for these formats. I would suggest using a flat earth projection as this is what Ungines internal coord system, physics, water, terrain is already using.

 

Then the next step would be to incorporate the tools fonta.romain suggested as part of the import process.


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