www.nathanbower.com



DTV MkII Applet


Be patient the applet will take ~45 seconds to load on a normal computer.

You will need a Java Runtime Environment, and the Java-3D plugin.
Most people dont have the runtime plugin and will need to download from here:
http://java3d.java.net/binary-builds.html Any Java3D version over 1.3. Its interesting to note that oracle / sun stopped developing the Java3D platform. Bit of a shame.

Controls


Left mouse + drag to rotate / tilt the view.
Middle mouse to zoom.
Right mouse to translate.

Information tidbits

  • The triangulation algorithm is a manual implementation of the Dulanay Scan line algorithm.
  • The texture is a 1024x1024 Jpeg, 1/2 that normally used in order to decrease download time.
  • The Data read is from a 400x400 sample grid, but only the most important points (about 20K vertexes, 40K triangles) are used in the irregular triangulation.
  • There is a viewpoint dependant clip plane behavior.
  • The mouse behaviour was written by me.
  • There are still some problems with my noral vector algoritm. Some triangles seem to have flipped.
I have a system (none applet - applets are limited to 64MB RAM) which can display multipule tiles, even upto all of the 800 tiles in the UK at the same time. I also have the imaging / DEM data for this display. The loaders / managers I wrote were an important part of the program, there is 4 GB (128 Million vertexes) of DEM data + ~9GB for each of the Imagery datasets, and for these to fit into physical memory effecient loaders / managers are needed. I have actually recently aqcuired a higher resolution DEM with ~1/2 billion point samples.

I have many different appearences from wireframe to SPOT satellite data and plan to write a behavior to switch them in realtime.

Performance


In terms of performance, a modern graphics card should be able to render this scenegraph at the monitor's refresh rate. My Geforce3 Ti-200 achieves 85fps even with antialiasing and filtering on. See the JVM console for framerates and other statistics.

All comments welcome : nathan@bowern8.plus.com