Fwd: [GRASS-user] Generate 3D raster from two surfaces

[Soeren Gebbert]

Hello,
IMHO the result on the top of the volume data in paraview looks
correct, because the top elevation map as lower values as 75ft at the
NW  side.
I strongly recommend that you use the threshold filter and the cutting
tools of paraview to have a deeper insight of the result.

In case the 2d resolution is different from the 3d resolution
internally the 3d resolution in x,y plane is used to read the 2d
raster maps.

Best regards
Soeren

2011/2/21  <grass at sundquist.imapmail.org>:
> Soeren:
>
> Well, that sort-of worked (at least after I increased the cell size so
> paraview didn't crash), but it didn't produce exactly what I was
> looking for:
>
> http://public.sundquist.imapmail.org/paraview-2.png
>
> It is basically the rectangular block with the 800 x 900 x 75 foot
> dimensions, with the plan-view of the treatment area painted on the top
> and bottom (gray one side, red the other side).
>
> And actually, the shape shown on each side is not exactly the treatment
> area.  For this test example, the top and bottom surfaces have the same
> footprint (i.e. plan view).
>
> Here is the top: http://public.sundquist.imapmail.org/top.png
>
> and here is the bottom: http://public.sundquist.imapmail.org/bottom.png
>
> The bottom side of the "cube" (red outline, no screen shot) is similar
> in shape to the input rasters, allowing for increased cell size.
>
> But the top side (grey, in screenshot above) has some sections missing
> (for example, the rest of the NW corner).  It shouldn't have had
> sectiosn truncated, since my region was set from 0 to 75 feet elevation:
>
> GRASS 6.4> g.region res=1 res3=10 t=75 b=0 tbres=10
>
> and the top and bottom are within these bounds:
>
> GRASS 6.4> r.univar contours
> total null and non-null cells: 720000
> total null cells: 525599
>
> Of the non-null cells:
> ----------------------
> n: 194401
> minimum: 55.2507
> maximum: 71.2332
> range: 15.9825
> mean: 68.4245
> mean of absolute values: 68.4245
> standard deviation: 2.02751
> variance: 4.11078
> variation coefficient: 2.96313 %
> sum: 13301789.790035248
>  100%
>
> GRASS 6.4> r.univar bottom_2
> total null and non-null cells: 720000
> total null cells: 525599
>
> Of the non-null cells:
> ----------------------
> n: 194401
> minimum: 15.5567
> maximum: 45.1165
> range: 29.5598
> mean: 34.7136
> mean of absolute values: 34.7136
> standard deviation: 3.25303
> variance: 10.5822
> variation coefficient: 9.37105 %
> sum: 6748356.0299701691
>  100%
>
> Does it matter that I had different values for res and res3?
>
> J.S.
>
> On Mon, 21 Feb 2011 18:30:36 +0100, "Soeren Gebbert"
> <soerengebbert at googlemail.com> said:
>> Hi, try:
>>
>> r3.out.vtk input=volumemap output=/tmp/volumemap.vtk null=0.0
>>
>> Open it in paraview and press the Apply button (thats important).
>>
>> Then choose style -> representation -> surface in the Display tab and
>> then color by -> volumemap in the color tab. I suggest you use a
>> recent paraview version?
>>
>> To compute the number of cells between the surface and the bottom use
>> r3.mapcalc:
>>
>> r3.mapcalc "valid_cells = if(volumemap == 1, 1, null())"
>>
>> r3.univar valid_cells
>>
>> To avoid large vtk files while testing, you can reduce the region
>> resolution with g.region.
>>
>> Best regards Soeren
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-user
>