1. Visualization Knowledge Query Language (VKQL) Workshop Nicholas Del Rio University of Texas at El Paso Computer Science

2. Workshop Objectives Understand notion and purpose of visualization queries Understand why writing queries may be easier that writing visualization programs Learn the VKQL syntax and practice posing queries

3. Workshop Summary 1.Generating Visualizations Imperatively 2.Visualization Query 3.VKQL Syntax and Examples 4.Activity 1: Manual Inspection of Query 5.Activity 2: Copy and Pasting Examples 6.Conclusion

4. Velocity Model Visualization A set of isosurfaces – extracted from a seismic velocity model – Covers a region in southern New Mexico 8 km/s 3 km/s Depth

5. Visualizing the Velocity Model Generated by custom Java application – relied on Visualization Toolkit (VTK) for rendering – VTK was developed for rendering 3D visualizations – VTK is supported by Sandia, Los Alamos, ARL, and others Writing a custom visualization application: – may rely on third party package to support rendering – may need to perform some transformations on input dataset before rendering

6. Visualization Toolkits Visualization Toolkit (VTK) was used to render the velocity visualization VTK is a toolkit that provides functions such as: – Filtering – Gridding/interpolating – Mapping (i.e., transform data into views like isosurfaces) – Rendering the views Functions are referred to as operators – Generic mapping tools (GMT): 60 operators – VTK: hundreds of operators

7. Visualization Pipeline Model VTK requires that users write pipelines – the output of an operator feeds into the operator next in the pipeline sequence – first operator in pipeline is usually data reader – final operator in pipeline is usually renderer Thus the Java program that visualizes the velocity model can be seen as a pipeline of VTK operators It is up to the users to write these pipelines…

8. VTK Java Pipeline For Velocity Model vtkImageReader rdr = new vtkImageReader(); rdr.SetFileName(inputDatasetFilePath); rdr.SetDataScalarTypeToUnsignedShort(); rdr.SetDataByteOrderToLittleEndian(); rdr.SetFileDimensionality(3); rdr.SetDataOrigin(0,0,0); rdr.SetDataSpacing(1,1,1); rdr.SetDataExtent(0,230,0,25,0,68); rdr.SetNumberOfScalarComponents(1); rdr.FileLowerLeftOn(); rdr.Update(); vtkContourFilter contours = new vtkContourFilter(); contours.SetInput(rdr.GetOutput()); contours.GenerateValues(35,0.0,9000.0); vtkPolyDataMapper contMapper = new vtkPolyDataMapper(); contMapper.SetInput(contours.GetOutput()); contMapper.SetScalarRange(0.0,9000.0); vtkActor contActor = new vtkActor(); contActor.SetMapper(contMapper); contActor.RotateX(105); vtkRenderer ren1 = new vtkRenderer(); ren1.AddActor(contActor); ren1.AddActor2D(outlineActor); ren1.SetBackground(1,1,1); vtkRenderWindow renWin = new vtkRenderWindow(); renWin.SetOffScreenRendering(1); renWin.AddRenderer(ren1); renWin.SetSize(300,300); renWin.Render(); vtkJPEGWriter img = new vtkJPEGWriter(); img.SetInputConnection(renWin.GetOutputPort()); img.SetFileName(outputDatasetFilePath); img.SetQuality(100);

9. Pipeline of Visualization Operators vtkImageReader rdr = new vtkImageReader(); rdr.SetFileName(inputDatasetFilePath); rdr.SetDataScalarTypeToUnsignedShort(); rdr.SetDataByteOrderToLittleEndian(); rdr.SetFileDimensionality(3); rdr.SetDataOrigin(0,0,0); rdr.SetDataSpacing(1,1,1); rdr.SetDataExtent(0,230,0,25,0,68); rdr.SetNumberOfScalarComponents(1); rdr.FileLowerLeftOn(); rdr.Update(); vtkContourFilter contours = new vtkContourFilter(); contours.SetInput(rdr.GetOutput()); contours.GenerateValues(35,0.0,9000.0); vtkPolyDataMapper contMapper = new vtkPolyDataMapper(); contMapper.SetInput(contours.GetOutput()); contMapper.SetScalarRange(0.0,9000.0); vtkActor contActor = new vtkActor(); contActor.SetMapper(contMapper); contActor.RotateX(105); vtkRenderer ren1 = new vtkRenderer(); ren1.AddActor(contActor); ren1.AddActor2D(outlineActor); ren1.SetBackground(1,1,1); vtkRenderWindow renWin = new vtkRenderWindow(); renWin.SetOffScreenRendering(1); renWin.AddRenderer(ren1); renWin.SetSize(300,300); renWin.Render(); vtkJPEGWriter img = new vtkJPEGWriter(); img.SetInputConnection(renWin.GetOutputPort()); img.SetFileName(outputDatasetFilePath); img.SetQuality(100); Op 1 Op 2 Op 3 Op 5 Op 6 Op 7 Op 8

10. Different Types of Operators vtkImageReader rdr = new vtkImageReader(); rdr.SetFileName(inputDatasetFilePath); rdr.SetDataScalarTypeToUnsignedShort(); rdr.SetDataByteOrderToLittleEndian(); rdr.SetFileDimensionality(3); rdr.SetDataOrigin(0,0,0); rdr.SetDataSpacing(1,1,1); rdr.SetDataExtent(0,230,0,25,0,68); rdr.SetNumberOfScalarComponents(1); rdr.FileLowerLeftOn(); rdr.Update(); vtkContourFilter contours = new vtkContourFilter(); contours.SetInput(rdr.GetOutput()); contours.GenerateValues(35,0.0,9000.0); vtkPolyDataMapper contMapper = new vtkPolyDataMapper(); contMapper.SetInput(contours.GetOutput()); contMapper.SetScalarRange(0.0,9000.0); vtkActor contActor = new vtkActor(); contActor.SetMapper(contMapper); contActor.RotateX(105); vtkRenderer ren1 = new vtkRenderer(); ren1.AddActor(contActor); ren1.AddActor2D(outlineActor); ren1.SetBackground(1,1,1); vtkRenderWindow renWin = new vtkRenderWindow(); renWin.SetOffScreenRendering(1); renWin.AddRenderer(ren1); renWin.SetSize(300,300); renWin.Render(); vtkJPEGWriter img = new vtkJPEGWriter(); img.SetInputConnection(renWin.GetOutputPort()); img.SetFileName(outputDatasetFilePath); img.SetQuality(100); Op 1 Op 2 Op 3 Op 5 Op 6 Op 7 Op 8 Transformer View Mapper Renderer Transformer

11. Operators are Parameterized vtkImageReader rdr = new vtkImageReader(); rdr.SetFileName(inputDatasetFilePath); rdr.SetDataScalarTypeToUnsignedShort(); rdr.SetDataByteOrderToLittleEndian(); rdr.SetFileDimensionality(3); rdr.SetDataOrigin(0,0,0); rdr.SetDataSpacing(1,1,1); rdr.SetDataExtent(0,230,0,25,0,68); rdr.SetNumberOfScalarComponents(1); rdr.FileLowerLeftOn(); rdr.Update(); vtkContourFilter contours = new vtkContourFilter(); contours.SetInput(rdr.GetOutput()); contours.GenerateValues(35,0.0,9000.0); vtkPolyDataMapper contMapper = new vtkPolyDataMapper(); contMapper.SetInput(contours.GetOutput()); contMapper.SetScalarRange(0.0,9000.0); vtkActor contActor = new vtkActor(); contActor.SetMapper(contMapper); contActor.RotateX(105); vtkRenderer ren1 = new vtkRenderer(); ren1.AddActor(contActor); ren1.AddActor2D(outlineActor); ren1.SetBackground(1,1,1); vtkRenderWindow renWin = new vtkRenderWindow(); renWin.SetOffScreenRendering(1); renWin.AddRenderer(ren1); renWin.SetSize(300,300); renWin.Render(); vtkJPEGWriter img = new vtkJPEGWriter(); img.SetInputConnection(renWin.GetOutputPort()); img.SetFileName(outputDatasetFilePath); img.SetQuality(100); Op 1 Op 2 Op 3 Op 5 Op 6 Op 7 Op 8 P1 P2 P5 P6 P7 P8 P9 P3 P4

12. Declarative Requests Many user skills needed to visualize data Aside from cognitive aspects of visualization, a large part of the problem is engineering Stems from fact that we generate visualizations imperatively (i.e., write code) Can we provide a means for users to generate visualizations declaratively (i.e., generate what visualization they want without having to write code)?

13. Workshop Summary 1.Generating Visualizations Imperatively 2.Visualization Query 3.VKQL Syntax and Examples 4.Activity 1: Manual Inspection of Query 5.Activity 2: Copy and Pasting Examples 6.Conclusion

14. Visualization Query (AND(hasView ?VIS isosurfaces) (hasContent ?VIS http://vel.3d) (hasFormat ?VIS floatArray) (hasType ?VIS velocityData) (viewedBy ?VIS mozilla-firefox) (hasValue numContours 36)) Desired View URL of Data to visualize Semantic Type of dataset WDO types (UTEP) Format of dataset ParameterArgumentViewer The velocity model visualization was actually a result of a visualization query Requested Visualization

15. Visualization Queries and SQL Visualization queries mirror SQL queries – query request is specified declaratively – request is then translated into a query plan – query plan computes the result requested by the query Information specified in visualization queries is used to derive pipelines rather than query plans The pipeline in turn generates the visualization requested in the query

16. Information Needed to Write Queries At a minimum you need to know: – The type of your dataset (e.g., gravity, seismic) – The format it is stored in (e.g., netCDF) – The URL of your dataset With only above info, all possible visualizations will be returned (wildcard) For more control, you need to know: – What view you want (i.e., chart, isolines, volume) – The appropriate values for operator parameters

17. Workshop Summary 1.Generating Visualizations Imperatively 2.Visualization Query 3.VKQL Syntax and Examples 4.Activity 1: Manual Inspection of Query 5.Activity 2: Copy and Pasting Examples 6.Conclusion

18. VKQL Syntax A conjunction of Prolog statements that contain: – hasView( -DATA, ?VIEW) – hasContent(-DATA, +URL), – hasType(-DATA, +TYPE), – hasFormat(-DATA, +FORMAT) – [hasValue(+PARAM, +VALUE)] Variable NameMeaning DATAThe requested visualization VIEWThe view (e.g., 2D plot, isolines, volume) URLURL of information to be visualized TYPESemantic Type of Data (e.g., gravity, 3DVelocity) FORMATFormat of data (e.g., netCDF, ascii-tabular) PARAMAn operator parameter VALUEArgument passed to PARAM SymbolMeaning -Unbound ?Optional +Required

19. Workshop Summary 1.Generating Visualizations Imperatively 2.Visualization Query 3.VKQL Syntax and Examples 4.Activity 1: Manual Inspection of Query 5.Activity 2: Copy and Pasting Examples 6.Conclusion

20. Activity 1: Manual Inspection of Query Navigate to: http://trust.utep.edu/visko/vkql-examples/http://trust.utep.edu/visko/vkql-examples/ Refer to the first query specified on the page: 1.What viewer is the query requesting the system to target? 2.What view is the query requesting the system to generate? 3.What is the type and format of the dataset being visualized? 4.Are there any parameter bindings? If so what is the parameter bound to?

21. Workshop Summary 1.Generating Visualizations Imperatively 2.Visualization Query 3.VKQL Syntax and Examples 4.Activity 1: Manual Inspection of Query 5.Activity 2: Copy and Pasting Examples 6.Conclusion

22. Submitting VKQL Queries VKQL queries can be entered and executed at: http://trust.utep.edu/visko/vkql/ http://trust.utep.edu/visko/vkql/ You can build queries by selecting values from combo boxes You can type queries manually in a text box without any guidance or copy and paste an existing query

23. Activity 2: Pasting Examples Navigate to: http://trust.utep.edu/visko/vkql- examples/http://trust.utep.edu/visko/vkql- examples/ Copy query for: Gridded Time with Rotation Paste and Submit Query in Query Submission Page Try manually changing the values assigned to: – xRotation – yRotation – zRotation Resubmit with new bindings

24. Workshop Summary 1.Generating Visualizations Imperatively 2.Visualization Query 3.VKQL Syntax and Examples 4.Activity 1: Manual Inspection of Query 5.Activity 2: Copy and Pasting Examples 6.Conclusion

25. Conclusion Writing queries may be easier to request for visualization generation than writing imperative code VKQL Queries can be constructed a few ways using the VKQL Query Submit interface VKQL Queries can target more than a single toolkit for generation