[osg-users] newbie question about osgTerrain yet again

Chris 'Xenon' Hanson xenon at alphapixel.com
Mon Nov 23 13:31:41 PST 2009

Anton Lauridsen wrote:
> I have - by using the osgTerrain example code - constructed a heightmap based terraintile.
> I'm having two issues, the terrain is ridiculously slow, showing about 15 fps for a 1024x1024 map. showing a huge amount of time in the draw phase, what have I done wrong?

  Is this a single tile? 1024x1024x2 is two million polys.

  It's usually best to break this up into smaller tiles. OSGDEM/VPB uses 64x64 tiles, and
LODs each group of four of those into a smaller 64x64 tile, etc, etc.

> The other, which surprises me a bit, is how the osgTerrain::ContourLayer is applied, I would have expected the ContourLayer to apply to the Z axis rather than the X axis as can be seen on the attached image, what have I done wrong there?

  I am not familiar with this class.

  Is this actually terrain data? If so, why are you building it by hand as opposed to
letting VPB do it and manage the LOD for you?

> Thank you!
> Cheers,
> Anton

Chris 'Xenon' Hanson, omo sanza lettere                  Xenon AlphaPixel.com
PixelSense Landsat processing now available! http://www.alphapixel.com/demos/
"There is no Truth. There is only Perception. To Perceive is to Exist." - Xen

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