   Rendering topographical map from heightmap?
  Does anyone have a pointer on how to render a topographic map from a high-resolution heightmap.  As a starting point, I'd like to be able to draw a map something like this:http://www.ucmp.berkeley.edu/fosrec/images/MetzgerFig1.gifThe problem I've had to date is that most real height data is quite rough.  If you plot out all the points at a given elevation you don't get a smooth curve, but rather a jagged discontinuous set of points that vaguely form a curve.  I haven't found a nice way to smooth this set of points.  I assume a solution lies in sampling - either smoothing the underlying terrain data or in being selective about which points to plot, but I'd appreciate any points from anyone who's done work like this before.One last point - the final output I'm looking for is raster-based (static image), but I'm open to 3D geometry-based solutions as an intermediate step.  Down the road I'd like to be able to do slope-based shading, so that might make a fully 3d approach more appropriate.thanks!   
  The solution should be simple enough:At a 2x sized render target, render a fullscreen quad with the input heightfield bound as a texture. For each pixel, sample it's height value % (whatever your delta is). If the result is zero (ie it's frequencies match up) output a white pixel, otherwise black.The goal here, is that you can add a 'falloff' function so that 2-3 height values on either side of the line can also get shaded, but contribute a grey value, or something less bright.When you're done, down-sample the 2x image to the desired resolution. Your result should be some fairly nice lines with gradients.~Main   