[osg-users] Generate geometry from a digital elevation model

[Christian Buchner]

As our application will also have to do physical simulations based on this
height field data, I do not want to use external tools to do the conversion
into an OSG model

here's a minimal example for the HeightField / ShapeDrawable method
http://snipplr.com/view/30974/osg-height-field-example/

here's a minimal example for the Delauney method (minus the loading of the
image and texture)
https://github.com/xarray/osgRecipes/blob/master/cookbook/chapter10/ch10_01/delaunay.cpp

I guess I will just try both methods. The only missing piece seems to be a
loading function or plug-in for height field Files in ".asc" format. But
the format is trivially simple.


2015-05-21 9:26 GMT+02:00 Sebastian Messerschmidt <
sebastian.messerschmidt at gmx.de>:

>  Hi Christian,
>
> Have you checked if osgdem supports it? I think it will happily convert
> anything into osgTerrain which can be interpreted as height data by gdal ...
>
>     Hi,
>
>  I am currently wondering which is the better way to go from a simple
> digital elevation model (ESRI ASCII Grid format) to a geometry. The model
> has a very limited area and resolution.
>
>  These are the two methods I find feasible with stock OSG features:
>
>  Either I could feed all the 3D points on the grid into the
> osgUtil::DelaunayTriangulator. However I noticed this class generates
> normals that require a BIND_PER_PRIMITIVE - possibly causing a fallback to
> the slow rendering path.
>
>  Alternatively I could put the data into an osg::HeightField and use a
> ShapeDrawable to display it.
>
>  Which of the two methods is perferable from a performance standpoint?
> What I would like to get is a bit of a simplification of the geometry,
> where larger triangles are used in areas with less surface features. Which
> of the two methods can provide this?
>
>  I do not want to use osgEarth, as it is a bit too big in scope for my
> purpose and it has a lot of extra dependencies.
>
>   Christian
>
>
>
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