Open Source (free) three-dimensional GIS (terrain, games)

Write your ideas First:

To make a simple terrain roaming, consider developing directly in WW, or find a development component in the form of a control.

The biggest expectations are:

1. Support for Google SketchUp, fast and intelligent three-dimensional modeling

2. Design patterns do a good job, preferably in the form of components, and then develop the application

3. Performance better, for indexing technology, memory management, etc.

4. Client independent version and customer server-side coupling version optimization

5. Release the data from the server.

. NET Platform

1.WorldWind
The popularity is very high, the introduction is also very whole. Link here at NASA World Wind
Currently divided into. NET versions andJavaVersion.
Development language: C#.java
Rendering mode: Directx,opengl (Java)

Advantages of WorldWind
WorldWind software architecture should be very good, very good. Open design, make the extension of WorldWind very convenient and fast, there are hundreds of various kinds of plug-ins, many plug-ins are very interesting and practical. Using. NET and Java, it is relatively easy to study how it works.
Relatively speaking, the. NET version is easier to dig into. Java version of the strict object-oriented approach to the use of the Java version of the simplification, but not in depth than. NET Easy.
When I used to communicate, I often recommend WorldWind. Very good and very powerful.

The. NET version is described here.

The following defects can not conceal the luster of WorldWind.

WorldWind's flaws
Overall architecture design is not too much of a problem. The main points in the interior
1. Slow speed. There are several reasons for the slow problem of worldwind in actual use.
AVideoData organization is confusing. Since WorldWind is designed for the system, it is the integration of various data in various industries. Therefore, his design-time compatibility, resulting in the same region of data acquisition duplication (accounted for memory resources), different data acquisition server speed inconsistent effect.
b) C # exception. Catching exceptions takes up worldwind most of the time. Causes a serious pause in display and data acquisition.
c) Dynamic generation of SRTM. If you want to download the SRTM like a drawing tool, it's impossible.
d) queuedownload The actual operation, in the event of anomalies and errors, will cause the data download to pause. The perspective needs to be re-adjusted. and seemingly multi-threaded download, the actual effect is not obvious. This causes the display to appear to be paused.
2. Three-dimensional support ability is slightly worse.
Especially in terms of model support, although there is a modelfeature class tothree-dimensionalShow. Here are the questions:
A) Lod is not supported, although the. x file is designed to support it, but obviously modelfeature does not support it.
b) The model shows drift. When you zoom in to the most detailed, you will find that the model is shaking left and right.
c) The model is not organized as tile. There are problems with Cache, memory, release, and so on.
3. Vector support
WorldWind's vector processing display class is confusing. The effect is not too good.
4.KML Support
It is possible to support KML through a plug-in, but there is still a lot of work to do to achieve GoogleEarth's addition and other functions.
5. Memory leaks
Supposedly, C # has no memory leaks. The problem is that the texture of the quadtile.dispose,d3d is not cleaned up. Make the resources occupy more and more, the speed is more and more slow
6.DEM Display defects
Each tile is not smoothed, often with deep pits and suspended.
7. Black Edge of image
Most WorldWind-based software can see black edges and jagged edges that are visible at the edge of the image. The reason for this is JPG compression, which occurs when black penetration blends leading to black edge aliasing. Two solutions, a) use PNG at the edge of the strip. b) strict data organization.

Domestic application of WorldWind
It can be said that many domestic experts have solved the above problems, and carry forward the advantages of WorldWind. Typical representative evglobe and so on. is not easy, from a certain point of view, is indeed independent research and development.

Non-. NET Platform

2.OSSIMPlanet
Link:ossimplanet
Development language: C + +
Rendering mode: OpenGL
Compared to WorldWind, fame is too big. Although recommended, I generally do not recommend it, but he is really another very powerful open sourceDigital Earth。 The reason I don't recommend it is:
1) based on C + +. Light studies know it costs a lot of money, which is not very suitable for domestic companies and units. High threshold, long time, slow effect.
2) less relevant information. It involves too many large open-source libraries, while domestic translators have a relatively small amount of information. Unlike WorldWind, the source code can be opened to dry.

But I like it very much, asTechnologyStaff, I recommend everyone to see. A lot of fun and knowledge in it. Very elegant, very connotation, worth collecting.

Ossimplanet Advantages
1) based on OSG (open Scene Graph), a very large and very industrial mature open source software. This is very appealing to me. Many domestic companies adopt, such as Xi ' an race can. Address: http://www.3snews.net/html/71/www.openscenegraph.org
Only OSG can list very many articles, the benefits of using OSG are greatly enumerated. It takes a lot of space to describe it clearly. We've got it here.
2) smooth and quick and efficient display effect.
3) as a platform, he covers a wide range of content, such as you can use OSG to make comparable terrabuilder software. Support most vectors, images, and model files with GDAL+OSG.
4) Perfect model support. Needless to say LOD, even the whole city is loaded with a little problem. In the long-ago, there was a virtual city called VTP Open source software.
5) Specialization, indeed very professional.
6) Scripting support. By using OSG's Osginterper (which is really fantastic), you can quickly bind Python,lua,javascript,ruby.
7) Want to know more advantages, or go to the next to see it.

Ossimplanet defects
Technically speaking, Ossimplanet's flaws are almost impossible. However, as stated above, it takes a lot of investment and money to form a product and a solution based on it. So its mishap is that it is not suitable for commercialization.

Ossimplanet Domestic Application
A few years ago, I had a chat with a development studio. They used OSG and the digital Earth, which was developed based on OSG, and referenced ossimplanet but were not used directly. Therefore, domestic applications, No.
This studio product is named Virtualterran. Later seems to become a mapok (unsure, know please contact me)

3.gps3d
Address: http://www.3snews.net/html/71/www.mgix.com/gps3d/
This open source software should be more focused on GPS functionality. It also contains some of the functions of the three-dimensional Earth.
Development language: C + +
Rendering mode: Opengl

This open source software is very small and very practical. It's very good as a technical reference. The parts you can refer to are latitude-to-three-dimensional coordinates, remote calls to WMS, WFS, and three-dimensional display of tiles.

Shortcomings are not much to say, after all, the direction is inconsistent, can not be a platform to request it.

4.earth3d
Address: http://www.3snews.net/html/71/www.earth3d.org
This open source software is suitable for preliminary study of three-dimensional Earth. It shows the three-dimensional Earth and shows the border line.
Development language: C + +
Rendering mode: Opengl

As a preliminary study, it's good. After all, the first step in the beginning is how to display the three-dimensional Earth and attach modis data. It can also show the boundaries of the country. Very good reference.

5. Other more open source software
So far, I found the open source software is the above 4 kinds, if you know more, please tell me.

Summarize:
1.WorldWind is the most mature and most suitable for commercialization.
2. Technology Best Ossimplanet

Open Source (free) three-dimensional GIS (terrain, game) platform information under other. NET Platforms

Axiom: Open source 3D game engine, is the famous open Source Engine ogre. NET version. The source code is constructed entirely in C #, mainly in the graphics section.
Realmforge: Open source 3d game engine, the graphics part of the axiom, and the combination and write some other network, artificial intelligence and other modules, completely by C # constructs.

and Google Earth,

Axiom
The Axiom 3D engine is a open-source, cross-platform 3D Graphics Rendering Engine for. NET and Mono.  The engine is a high-performance C # Port of the powerful OGRE engine.  Its flexible component-oriented architecture allows easy extension and provides full support for both DirectX and OpenGL. The engine is a also cross platform supporting both Windows and Linux operating systems.

Realmforge:
The. NET 3D game engine predecessor to Visual3D.NET (Www.visual3d.net), which are a framework and toolset for the Visual de Sign and development of the 3D games, simulations, and interactive environments using C #,. NET 2.0, and XNA.

Irrlicht
The Irrlicht engine is a open source high performance realtime 3D Engine written and usable in C + + and also available for . NET languages. It is completely cross-platform, using D3D, OpenGL and its own software renderer, and have all of the State-of-the-art feat Ures which can be found in commercial 3d engines.
We ve got a huge active community, and there is lots of projects in development so use the engine. You can find enhancements-Irrlicht all over the web, like alternative terrain renderers, portal renderers, exporters, World layers, tutorials, editors, language bindings for Java, Perl, Ruby, Basic, Python, Lua, and so on. And best of all:it ' s completely free.

Non-. NET Platform

Orge: Rated very high open source 3D game engine. Built using C + +, mainly in the graphics section.

Terravision
Http://www.ai.sri.com/digitalearth/index.shtml

Http://www.ai.sri.com/tvgeo/download_full.shtml

Https://sourceforge.net/projects/terravision

http://www.ai.sri.com/tvgeo/

Terravisiontm is a Open Source distributed, interactive terrain visualization system developed by SRI International. It allows users to navigate, in real time, through a-Z graphical representation of a real landscape created from Elevati On data and aerial images of this landscape. There is many terrain visualization tools on the market, but here is some of the features that make TERRAVISIONTM unique :

New:full Open Source hosted on SourceForge.
Terravisiontm can browse huge datasets, in the order of terabytes.
All data can is distributed over multiple servers across the WEB.
GEOVRML VRML and models can be overlaid, e.g. buildings, wind vectors, etc.
Terravision can access OGC Web Map Servers (WMS) [More]
Datasets of different size, resolution, source, and coordinate system are supported.
New:terravision Server on Internet2.
Available for Windows, Linux, and SGI platforms.
New:version 6.0 released

Open Source (free) three-dimensional GIS (terrain, games)