Real World Topo

Is it possible in SL to model parcels of land based on topograhic contours from RL?

Topographic "maps", not unlike USGS maps of contours, are what I want to use to grade the parcel I own to reflect real world ground features.

Any help?

Possible yes, easy...maybe. If you are working with a full private island you could convert that topographical map into a height map for use in the terrain .raw file. Depending on how the topographical map is formated this could either be painstakingly difficult or very easy.

If you are not working with a private island you could still attempt to manually edit the land to match your map.

You can. I've done it before. But SL's terrain is severely limited as compared to real terrain. A sim is only 256 Meters by 256 Meters in size, or about 16 acres. And for most practical purposes, anything over 100 Meters in elevation looks incredibly bad if you only have a single sim to terraform in. Compared to real mountains, the highest possible point of land in SL, 492 M above the standard 20M sea level, is barely a decent foothill.

As to the 'how' of it: You have to work on a Private Island that you own, or you need the cooperation of the sim owner, for only a sim owner can upload a .raw file to their sim. Uploading a .raw file changes the terrain of the entire sim, so this is best done on an unoccupied, new sim.

Look in the SL WIKI for information on how to make .raw files. Start with a Photoshop file that has layers for your elevations, and draw the irregular contours from the terrain profile map on each layer. Now fill the contour layers with solid greys, where solid black (0,0,0) is zero Meters, and pure white (255,255,255) is 255 Meters. The result will get gradually lighter as things get higher. Flatten a copy, and then use a Gausian blur to smooth the layers into your heightmap. Scale this map down to 256 pixels by 256 pixels in size, and add that to chanel zero of the .raw file. (I use Backhoe on a Mac to do that, but there are sililar utilities for Windows, and I think the latest versions of Photoshop can save to .raw format directly.)

There is also a 'multiplier' layer in the .raw file, that can be used to alter the results of the height map, by as much as a 2X multiplier (yeilding a highest possible elevation of 512 Meters, or 492 M above the 20 M standard sea level). I usually set my multiplier to 0.50, so I can only go to 128 Meters elevation, but I get twice the vertical resolution, for smoother hills.