The plane-layer intersection lines could be useful too. But since what we have
is a stack of flatfields of (x, y) --> z then "clipping" the layers by some
plane(s) could be a useful operation and visualization. So the result of
clipping a layer by one or more planes would be a new layer which is like the
original layer but minus some part of it.
-- mohamad
LANL
Bill Hibbard wrote:
> Hi Mohamad and Ugo,
>
> > The idea is to be able to depict a movable plane that sweeps the
> > DEM and sends the data of the intersection curve to the 2D display.
>
> If the DEM is "FlatField elevation" with MathType ((x, y) -> z) then
> to make a vertical cutting plane, construct "Gridded2DSet cutting_set"
> with MathType Set(x, y) and manifold dimension = 1, whose samples
> lie along the line in the (x, y) plane that is the intersection of
> the (x, y) plane with the vertical cutting plane. Then:
>
> FlatField cut_elevation = (FlatField)
> elevation.resample(cutting_set, Data.WEIGHTED_AVERAGE, Data.NO_ERRORS);
>
> and cut_elevation will be displayed in your 3-D DEM display as the
> curve that is the intersection of your DEM with the vertical cutting
> plane. For your 2-D display, construct another RealType w that
> represents location along the line in the (x, y) plane and construct
> "Gridded1DSet dem2d_samples" with MathType Set(w) and whose samples are
> the w locations of the samples of cutting_set. Then:
>
> FunctionType dem2d_type = new FunctionType(w, z);
> FlatField dem_2d = newFlatField(dem2d_type, dem2d_samples);
> double[][] values = cut_elevation.getValues();
> dem_2d.setSamples(values);
>
> Now you can display dem_2d in 2-D with the ScalarMaps:
>
> ScalarMap(w, Display.XAxis);
> ScalarMap(z, Display.YAxis);
>
> If your DEM display includes 3-D FlatFields [i.e., MathType
> ((x, y, z) -> attribute)] representing sub-surface data, then you can do
> something similar by defining a "Gridded3DSet cutting_plane" with MathType
> Set(x, y, z) and manifold dimension = 2, whose samples are a 2-D grid lying
> on the cutting plane. Then resample the 3-D FlatFields to cutting_plane,
> etc.
>
> Cheers,
> Bill
> ----------------------------------------------------------
> Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI 53706
> hibbard@xxxxxxxxxxxxxxxxx 608-263-4427 fax: 608-263-6738
> http://www.ssec.wisc.edu/~billh/vis.html
