I need a VTK format for my mesh
Altair EmployeeHi,I am going to work with Fenics to run my problems. Actually, we should have vtk format for my meshes to run Fenics. There is 2 formats for vtk, one is vtp where it is for surface mesh and another format is vtu for volume mesh. I need a code for exporting my mesh to this formats. And for every surface I need a vtp outcome. For example, if I have 10 surfaces, and one volume, I need a code to give me 11 files, 10 files for each surfaces, and 1 file for my volume. Does it make sense? I could pay for this code who want to write it.
Answers
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I can make template for that.
Please describe your vtp and vtu formats
If it is not so long, it's free for you!
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what should I describe for you? I need a vtk files which I can easily open them in Paraview.
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Could you give me an example of vtk file?
I think it is a text file that has node coordinates, element definition, isn't it?
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I will attach some vtk file that you can easily open it in text file and paraview. . the vtu is volume and the vtp is one of my surfaces.
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Is this you mentioning?
http://www.earthmodels.org/software/vtk-and-paraview/vtk-file-formats
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yes thats it.
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OK. let's have a look
I think the template will be simple.
just I am trying to understand its format, where is node coodinate, node id, element nodes,...etc
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Maybe, coordinates are here, aren't they?
<?xml version="1.0" encoding="UTF-8"?>
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yes thats it
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This is clearly node IDs, but I cannot find out number 4:
what is 'RangeMin'?
<?xml version="1.0" encoding="UTF-8"?>
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This looks like element definition. Are they hexagon elements?
And I see, they refer to indices but not IDs of nodes, am I right?
<?xml version="1.0" encoding="UTF-8"?>
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no there are tetrahedral. and I myself cannot find out the what rangemin is. I am asking my professor to answer me.
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<?xml version="1.0" encoding="UTF-8"?>
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<?xml version="1.0" encoding="UTF-8"?>
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this is the surface and the volume mesh that i can see in paraview
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that surface is one of my surfaces.
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I see,
so the surface is formed by triangle elements? and each of them has 6 node (3 vertices and 3 mid-points)?
it is tria6 element type in Hypermesh, isn't it?
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Yes it is triangle, and No, my mesh does not have middle point
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Ok I see.
so first 3 indices is for 1st triangle, and so on...
<?xml version="1.0" encoding="UTF-8"?>
I am making initial template to check...
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I think we need to couple template with some tcl codes
because the format is not suitable to be output by pure template...
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Do you know what is 'offset'?
<?xml version="1.0" encoding="UTF-8"?>
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oh no, that was my problem too
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I found it,
the offset field will define type of poly, if it is shifted by 3 => it is triangle element
But I am stuck with connectivity field, it doesn't refer to global node ids but indices
and searching how can we generate the indices
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Hi,
I wrote it. Below proc will help to export vtp, a template is not neccessary.
example running it from command window of hypermesh:
p_Export2DToVtpFile MyModel.vtp all; #export all 2d elems
p_Export2DToVtpFile MyModel.vtp displayed; #export only displayed 2d elems
proc p_Export2DToVtpFile {FilePath {displayed_or_all displayed}} { *createmark elems 1 $displayed_or_all *createmark elems 2 'by config' tria3 quad4 tria6 quad8 *markintersection elems 1 elems 2 set ElemList [hm_getmark elems 1] set ElemNodeList [join [hm_getvalue elems mark=1 dataname=nodes]] set ElemNodeCount [join [hm_getvalue elems mark=1 dataname=nodecount]] set CompList [hm_getvalue elems mark=1 dataname=collector.id] eval *createmark nodes 1 $ElemNodeList set NodeList [hm_getmark nodes 1] set CoordList [join [hm_getvalue nodes mark=1 dataname=coordinates]] set _NodeList [lsort -integer $NodeList] set MinNodeId [lindex $_NodeList 0] set MaxNodeId [lindex $_NodeList end] set _ElemList [lsort -integer $ElemList] set MinElemId [lindex $_ElemList 0] set MaxElemId [lindex $_ElemList end] set NodeCount [llength $NodeList] set ElemCount [llength $ElemList] set Buffer {<VTKFile type='PolyData' version='1.0' byte_order='LittleEndian' header_type='UInt64'>} append Buffer \n { <PolyData>} append Buffer \n { <Piece NumberOfPoints='NodeCount' NumberOfPolys='ElemCount'>} append Buffer \n { <PointData Scalars='GlobalNodeID'>} append Buffer \n { <DataArray type='Int32' Name='GlobalNodeID' format='ascii' RangeMin='MinNodeId' RangeMax='MaxNodeId'>} set Buffer [string map [list NodeCount $NodeCount ElemCount $ElemCount MinNodeId $MinNodeId MaxNodeId $MaxNodeId] $Buffer] append Buffer \n $NodeList append Buffer \n { </DataArray>} append Buffer \n { </PointData>} append Buffer \n { <CellData Scalars='ModelFaceID'>} append Buffer \n { <DataArray type='Int32' Name='GlobalElementID' format='ascii' } append Buffer 'RangeMin=\'$MinElemId\' RangeMax=\'$MaxElemId\'>' append Buffer \n $ElemList append Buffer \n { </DataArray>} set _CompList [lsort -integer $CompList] set MinCompId [lindex $_CompList 0] set MaxCompId [lindex $_CompList end] append Buffer \n { <DataArray type='Int32' Name='ModelFaceID' format='ascii' } append Buffer 'RangeMin=\'$MinCompId\' RangeMax=\'$MaxCompId\'>' append Buffer \n $CompList append Buffer \n { </DataArray>} append Buffer \n { </CellData>} append Buffer \n { <Points>} set _CoordList [lsort -real $CoordList] set MinCoord [lindex $_CoordList 0] set MaxCoord [lindex $_CoordList end] append Buffer \n { <DataArray type='Float32' Name='Points' NumberOfComponents='3' format='ascii' } append Buffer 'RangeMin=\'$MinCoord\' RangeMax=\'$MaxCoord\'>' append Buffer \n $CoordList append Buffer \n { </DataArray>} append Buffer \n { </Points>} append Buffer \n { <Polys>} append Buffer \n { <DataArray type='Int64' Name='connectivity' format='ascii' } append Buffer 'RangeMin=\'$MinNodeId\' RangeMax=\'$MaxNodeId\'>' #append Buffer \n $ElemNodeList; #oh, it doesn't refer to global node ids but indices set i -1 foreach NodeId $NodeList { set Index($NodeId) [incr i] } set Indices {} foreach NodeId $ElemNodeList { lappend Indices $Index($NodeId) } append Buffer \n $Indices append Buffer \n { </DataArray>} set Offsets {} set InitOffset 0 foreach NodeCount $ElemNodeCount { lappend Offsets [incr InitOffset $NodeCount] } set MinOffset [lindex $Offsets 0] set MaxOffset [lindex $Offsets end] append Buffer \n { <DataArray type='Int64' Name='offsets' format='ascii' } append Buffer 'RangeMin=\'$MinOffset\' RangeMax=\'$MaxOffset\'>' append Buffer \n $Offsets append Buffer \n { </DataArray>} append Buffer \n { </Polys>} append Buffer \n { </Piece>} append Buffer \n { </PolyData>} append Buffer \n {</VTKFile>} *clearmark nodes 1 *clearmark elems 1 *clearmark elems 2 set fpt [open $FilePath w] #fconfigure $fpt -encoding utf-8 puts $fpt $Buffer close $fpt set FilePath }
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Thank you so much, it helped me alot, but what about the volume mesh which has vtu format?
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Do it your self, base on my script
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thank you so muchh.
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Hello @, first of all thank you very much for your work, I know this is very late but I really need to export a surface mesh to VTK and I can't seem to get your script to work, I have copied the script you pasted, pasted it onto a notepad and saved it with a .tcl extension.
I have opened it with HyperMath and have separated all the lines, I am uploading the result here (I have uploaded it with a .txt extension so that it will allow me to upload it).
I have then tried to run the command you posted on the command view of Hypermesh (making sure I was in the correct folder) while my mesh was open, but I get the error "hm_getvalue: Mark is empty."
Am I missing any steps? Is the file I uploaded correctly modified? Is the extension .tcl ok or does it need to have a different extension?. Thank you very much for your help.
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