Monday, June 27, 2005

Map Trip - An Animation

This short animation is a trip into the theoretical third dimension of the Second Life map. It's just supposed to be a bit of silly fun. It's a 13 second Quicktime movie and the file is 3.2 megabytes.

Click the image to download.

Saturday, June 25, 2005

SL Terrain Mapping Done

I've finished mapping the terrain of the continent of Second Life. Below is a map of the grid generated in the style of the in-world map. I added the ability to create this type of map because SL residents are already familiar with it. I'm working now on interactive grid maps for the web and for Windows .NET.

Click for larger version.

Tuesday, June 21, 2005

Second Life void sims

Linden Lab has been adding "void" sims to fill in empty areas in the Second Life grid. This means people will be able to travel through these spaces instead of going around. Apparently the servers being used are the old servers of sims which have been upgraded to new hardware. Here's a picture of the terrain of a set of new void sims along the southern coast of the Japanese sims. It's cool that they put in detail such as the long underwater valley.

Saturday, June 18, 2005

Sample Terrain Data and MATLAB

The terrain data I'm collecting in Second Life is stored in comma delimited text files like this one for Seacliff. The first column in each row is the y coordinate of that row's data. If you happen to have access to MATLAB, you can create a 3D image from this data in three lines:

S = dlmread('Seacliff_Terrain.txt',',');
S = S(:,2:end);
surf (S); figure(gcf)

The first line reads the data into a matrix. The second line removes the first column. The third line plots the surface.

Of course you can create a lot of other different plots. Here's a contour plot with default settings.

Thursday, June 16, 2005

Parametric Curves in 3D

I learned about parametric curves recently and thought they were so neat I decided to make some in Second Life. I scripted a tool for making them. If I find the time to polish it up I'll put it out for free like ShapeMaker.

Here is an epitrochoid. I think it took between 150 and 200 prims to get it this smooth.

And here is something I called a torus ribbon. I don't know if it's an established curve of some sort, it was just an idea I had. It's supposed to be the path of a spiral along the surface of a torus. As you can see I messed up the equation slightly so I'll have to debug it.

3D Grid Viewer Update

I've been learning OpenGL programming by writing a 3D grid viewer which uses the terrain data I'm collecting from Second Life. I put an old screen shot below. I recently changed the file format for the height data from a grayscale bitmap to a text file. Since then I've updated the viewer to use the new format and implemented a simple level of detail mechanism which operates on a sim by sim basis. The next step is frustum culling of sims.

Grid Mapping Update

I've been mapping the topography of the Second Life grid. I use a scripted object with multiple scripts to scan the terrain at 2 meter intervals to a precision of .1 meters. Here's an image showing my progress. I'm ignorning the private island sims for now, because they change so quickly.

Click to see the larger version. This image maps the height of the terrain to color hue.


This doesn't feel like a real blog yet. I have various projects included on my web site that I'd like to post updates about. A blog seems like a more practical way to do it than editing web pages. This will also allow people to comment or ask questions. For now these projects are all related to the virtual world of Second Life, but I'll probably be adding other things related to computer interfaces and 3D programming.