[vtkusers] extending vtkPolyDataAlgoritm

[John Biddiscombe]

I see that you are using Java and have already asked about 
SetNumberOfInputPorts in Java. The answer is use C++.

JB


> You need to ensure in your class that you SetNumberOfInputPorts(0) in 
> your constructor, what the error message is telling you is that it is 
> expecting an input, but none has been provided. If your code is a source 
> object (ie not a filter), then you can tell it no inputs are needed
> 
> JB
> 
> 
> Alexander MacLennan wrote:
>> Hi,
>>
>> I am getting the following error message when I use my own class that 
>> converts from OOGL to a format viewable using VTK
>>
>>
>>
>> ERROR: In 
>> /usr/student/tango/maclenna/cvs/VTK/Filtering/vtkDemandDrivenPipeline.cxx, 
>> line 692
>> vtkStreamingDemandDrivenPipeline (0x8073228): Input port 0 of 
>> algorithm vtkPolyDataAlgorithm(0x8074588) has 0 connections but is not 
>> optional.
>>
>> Its vtk compiled from CVS as of a few days ago.
>>
>> Does anyone have some hints?
>>
>> cheers
>>
>> alex
>>
>> Here is my class:
>>
>>
>>
>> import java.awt.color.ColorSpace;
>>
>> public class vtkOOGLtoVtk extends vtk.vtkPolyDataAlgorithm {
>>     private OOGLObject o;
>>
>>     public void setOOGL(OOGLObject o) {
>>         this.o = o;
>>     }
>>     
>>     /**
>>      * Get oogl object in vtk format
>>      * Follows the pattern set by vtkPLYReader.cxx
>>      *
>>      * @param request
>>      * @param inputVector
>>      * @param outputVector
>>      * @return
>>      */
>>     public int RequestData(vtkInformation request,
>>             vtkInformationVector inputVector, vtkInformationVector 
>> outputVector) {
>>                // Ape the stuff from vtkPLYReader until I know whats 
>> going on
>>         vtkInformation outInfo = outputVector.GetInformationObject(0);
>>                // Casting done with C++ example, not the best for java???
>>         vtkPolyData output = (vtkPolyData)outInfo.Get(new 
>> vtkInformationDataObjectKey());
>>         output.Initialize();
>>                        // Return value
>>         int result = 1;
>>                // Temp vertex holder
>>         Point3d v = null;
>>                // Temp face holder
>>         Point3i f = null;
>>                // Temp variable for testing number of colours defined 
>> for OOGL Object
>>         int count = 0;
>>                // Boolean variable for checking to see if RGB data 
>> available ( well HSV )
>>         boolean colourDataAvailable = false;
>>                // RGB values for points
>>         vtkUnsignedCharArray rgbPoints = null;
>>                // Temp variable for putting colour into table as rgb
>>         float[] colourComponents = null;
>>                // Test number of colours defined for vertices
>>         if ( o.getVertexColours() != null)
>>                 count = o.getVertexColours().size();
>>                if ( count > 0)
>>             colourDataAvailable = true;
>>                // If there are vertex colours then use RGB Points
>>         if (colourDataAvailable){
>>             rgbPoints = new vtkUnsignedCharArray();
>>             rgbPoints.SetName("RGB");
>>             output.GetPointData().SetScalars(rgbPoints);
>>             rgbPoints.Initialize();
>>             rgbPoints.SetNumberOfComponents(3);
>>             rgbPoints.SetNumberOfTuples (this.o.getVertices().size());
>>                    }
>>         // Don't worry about colours by face for the moment.. its not 
>> important
>>         // to implement this right now
>>                // Now load vertices into structure
>>         vtkPoints points = new vtkPoints();
>>         points.SetDataTypeToFloat();
>>         points.SetNumberOfPoints(this.o.getVertices().size());
>>                for ( int i = 0 ; i < o.getVertices().size(); i++){
>>             // Get the vertex values and set them in the point data 
>> object
>>             v = o.getVertices().get(i);
>>             points.SetPoint(i, v.x, v.y, v.z);
>>                        // If colours available insert them, converting 
>> from hsb to rgb
>>
>>             if (colourDataAvailable){
>>                 colourComponents = 
>> o.getVertexColours().get(i).get().getComponents(ColorSpace.getInstance(ColorSpace.TYPE_RGB), 
>> new float[3]);
>>                 rgbPoints.SetTuple3 (i, colourComponents[0], 
>> colourComponents[1], colourComponents[2]);
>>             }
>>         }
>>                // Now set the up the faces
>>         vtkCellArray polys = new vtkCellArray();
>>                // Allocate space for faces
>>         for (int i = 0; i < this.o.getFaceCount(); i++) {
>>             // Get face to insert
>>             f = this.o.getFaces().get(i);
>>
>>             // Tell ca that next cell is a triangle
>>             polys.InsertNextCell(3);
>>
>>             // Insert point reference values that
>>             // make up the face
>>             polys.InsertCellPoint(f.x);
>>             polys.InsertCellPoint(f.y);
>>             polys.InsertCellPoint (f.z);
>>         }
>>                       output.SetPolys(polys);
>>         output.SetPoints(points);
>>                               return result;
>>     }
>>
>> }
>>
>>
>> ------------------------------------------------------------------------
>>
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> 
> 


-- 
John Biddiscombe,                            email:biddisco @ cscs.ch
http://www.cscs.ch/about/BJohn.php
CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82