Failed to load data when use setFormulaSimple in vtkCalculator

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1

Hi, dear vtk.js experts：

I try to learn how to use vtkCalculator, this is example html code using setFormularSimple for testing:

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>

<body>
    <div id="renderer"></div>
    <script src="https://unpkg.com/vtk.js"></script>

    <script>
        // using vtk namespace
        const vtkActor = vtk.Rendering.Core.vtkActor;
        const vtkCalculator = vtk.Filters.General.vtkCalculator;
        const vtkMapper = vtk.Rendering.Core.vtkMapper;
        const vtkFullScreenRenderWindow = vtk.Rendering.Misc.vtkFullScreenRenderWindow;
        const vtkPlaneSource = vtk.Filters.Sources.vtkPlaneSource;

        const AttributeTypes = vtk.Common.DataModel.vtkDataSetAttributes.AttributeTypes;
        const FieldDataTypes = vtk.Common.DataModel.vtkDataSet.FieldAssociations;


        // ----------------------------------------------------------------------------
        // Standard rendering code setup
        // ----------------------------------------------------------------------------

        const fullScreenRenderer = vtkFullScreenRenderWindow.newInstance({
            background: [0, 0, 0],
        });
        const renderer = fullScreenRenderer.getRenderer();
        const renderWindow = fullScreenRenderer.getRenderWindow();

        // ----------------------------------------------------------------------------
        // Example code
        // ----------------------------------------------------------------------------

        const simpleFilter = vtkCalculator.newInstance();
        simpleFilter.setFormulaSimple(
            FieldDataTypes.POINT, // Generate an output array defined over points.
            [], // We don't request any point-data arrays because point coordinates are made available by default.
            'z', // Name the output array "z"
            (x) => (x[0] - 0.5) * (x[0] - 0.5) + (x[1] - 0.5) * (x[1] - 0.5) + 0.125
        ); // Our formula for z
        
        const planeSource = vtkPlaneSource.newInstance({
            xResolution: 25,
            yResolution: 25,
        });

        const planeMapper = vtkMapper.newInstance({
            interpolateScalarsBeforeMapping: true,
            useLookupTableScalarRange: true,
        });

        console.log("planeSource",planeSource.getOutputData().toJSON())

        simpleFilter.setInputConnection(planeSource.getOutputPort());
        
        console.log("simpleFilter",simpleFilter.getOutputData())

        const planeActor = vtkActor.newInstance();
        //planeMapper.setInputConnection(planeSource.getOutputPort());
        planeMapper.setInputConnection(simpleFilter.getOutputPort());
        
        planeActor.setMapper(planeMapper);
        planeActor.getProperty().setEdgeVisibility(true);

        renderer.addActor(planeActor);
        renderer.resetCamera();
        renderWindow.render();
    </script>
</body>
</html>

However, I got this error message:

vtk.js:2  Output array size could not be determined for {"name":"z","attribute":0,"numberOfComponents":1}.

Could you provide some suggestions about how to use the simpleFilter properly? Thanks a lot for the help!

2

I finally found that the issue is caused by

 const FieldDataTypes = vtk.Common.DataModel.vtkDataSet.FieldAssociations;

It should be

 const FieldDataTypes = vtk.Common.DataModel.vtkDataSet.FieldDataTypes;
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