[vtkusers] Interpolation of data..

[Rakesh Patil]

 Hi Bill,Thanks for your reply.. I implemented that technique and it works fine. As i said in my previous post, outsid range values are not interpolated.For example, pls see the attached image file for reference.. In the figure, the mesh which is generated, doesnt completely fall in the area of the scatter data.. In the rwo white patches, the values are not interpolated. I mean i dont get the actual result there in those areas (as there is no scatter points avail there)So, what can i do to get values for my entire mesh instead of getitng for partial mesh.??Either interolation or extrapolation.. Any means is available in VTK to implement this..??ThanksRegardsRakesh Patil Original message From:Bill Lorensen< bill.lorensen at gmail.com >Date: 24 Apr 10 18:15:33Subject:Re: [vtkusers] Interpolation of data..To: Rakesh Patil The last part of this example:http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerraindoes what you want.Basically,1) Add the lat/log and elevations to a polydata2
 ) Create a surface with Delaunay2D3) Add the points with unknown elevation to a vtkPoints4) Use a cell locator to cast infinite rays into the surface to findthe elevation.On Fri, Apr 23, 2010 at 9:50 PM, Rakesh Patilwrote:>>> Well,>> I was trying with this example:>> http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain>> In this example, there are two ways specified for interpolation.. One is> using> vtkProbeFilter and another is using vtkCellLocator>> First i tried using vtkProbeFilter. But failed getting the output.. But> using the> vtkCellLocator, i was able to produce interpolated values for the third> column of MeshG.>> After observation, i foound that only the region which is common in both the> grids,> was interpolated. So i was fully stuck wondering how to find the remaining> values..>> any comments..??>> Thanks>> Rakesh Patil>>  Original message > From:"Dean Inglis"< dean.inglis at camris.ca >> Date: 23 Apr 10 23:59:48> Subject: Re: Re:[vtkusers]Interpolation of dat
 a..> To: "Rakesh Patil">> How can you expect your mesh to get interpolated> when its z coordinate values are all 0> but the scatter data range in z from 700 to 900?> The bounds of each unstructured grid do not even> overlap / intersect!>> Dean>>> Hi,My both the meshes are unstructured grid. My application is based on>> FEA method.. ScatterG does contains scalars and the depth values are>> stored as a scalar array for scatterG..I dont want coordinate values to be>> interpolated.. As an example,scatterG contains data something like>> this,Points: 87.23 16.2690086.24 17.8753087.18 17.27700......and the>> scalar for scatterG is defined as 900530700......meshG contains>> points84.1217.83 081.3315.28 083.2418.28 0......So,, what i want to do is,>> using the third column of scatterG, i need to estimate the third column of>> meshG..Any ideas how it can be done.??ThanksRakesh Patil Original message>> From:"De an Inglis"< dean.inglis at camris.ca >Date: 23 Apr 10>> 20:16:47Subject:Re: Re
 :[vtkusers]Interpolation of data..To: "Rakesh Patil">> vtkProbeFlter will probe the scalar values ateach spatial location of your>> scattered points: youneed to have scalar, vector, or tensor data>> associatedwith the grid's points:scatterG>GetPointData()>SetScalars(>> somevt>> kDataArray );the vtkProbeFilter will not interpolate any coordinatevalues>> like x , y,z locations.If you have depth valuesin a vtkDataArray that>> correspond to the x, y, z locationsin your scatterG grid, then this should>> work.Does anyone know ifmaybe the input to the probe filter needs to be a>> structured data set likevtkPolyData? By the sound of your grid's name>> "mesh" , this sounds like structureddata.Can it be converted to a>> vtkPolyData?Also, you allocate a smart pointer as:vtkSmartPointer probe =>> vtkSmartPointer: :New()Dean Original Message From: "Rakesh Patil" To: Cc:>> Sent: Friday, April 23, 2010 9:40 AMSubject: Re: Re:[vtkusers]>> Interpolation of data..> Hi..I can independently vie
 w those grids... This>> is what I have done..vtkUnstructuredGrid *scatterG =>> MyApp::getInstance()>getScatterGrid();vtkUnstructuredGrid *meshG =>> MyApp::getInstance()>getMeshGrid();vtkSmartPointer probe =>>>> vtkSmartPointer::New();probe>SetSource(scatterG);probe>SetInput(meshG);probe>Update();vtkDataArr>> ay *data = probe>GetOutput()>GetPointData()>GetScalar();vtkDoubleArray>> *doubleArray =>>>> vtkDoubleArray::SafeDownCast(data);MyContour::getInstance()>setDisplayArray(doubleArray);After>> doing this, i click on contour display button, and the contour for>> bathymetry gets displayed for meshG.Initially, meshG doesnt have>> depth/elevation (z) value. z value is always 0 for every node point. x and>> y corresponds to the lon and lat respectively.But the scatter data>> contains lon, lat, and depth.. So, once the interpolation is done, i>> should get the bathymetry (depth/elevation) for meshG also..'MyContour' in>> the above code is the class which displays the contours for 
 wh> atever>> data is being passed.So, any suggestions or > comments..??ThanksRegards>> Rakesh Patil Original messageFrom:Dean Inglis< > dean.inglis at camris.ca >>> Date: 23 Apr 10 16:49:50 Subject:Re: > Re:[vtkusers]Interpolation of>> data.. To: "Rakesh Patil">>>>>> > Powered by www.kitware.com>> Visit other Kitware opensource projects at> http://www.kitware.com/opensource/opensource.html>> Please keep messages ontopic and check the VTK FAQ at:> http://www.vtk.org/Wiki/VTKFAQ>> Follow this link to subscribe/unsubscribe:> http://www.vtk.org/mailman/listinfo/vtkusers>> 
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