Cuberilles Statistical Volume Visualisation for Medical and Geological Data
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Transcript of Cuberilles Statistical Volume Visualisation for Medical and Geological Data
Cubrilles Statistical Volume Vis
Cuberilles Statistical Volume VisINF252 Visualization Final Project PresentationChristian Kehl
Design FocusCoupled interaction Statistics Volumestatistical 2D views (Avg/Max Intensity Proj.)Statistics per Dimension1D ray: Histogram, Profile, Semi-Variog.2D slice: Histogram, Semi-Variogram3D volume: HistogramConvolution responses; Histogram > PDFDesignDemoSpecificsReflection
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PDF: Probability Distribution Function2
Design Focus3D representation using Cuberilleswhy ? data sharing GPU 3D CPUGlyphing Cuberilles with Cubes or SpheresPreset Editor for Colour-Opacity changesLensing for Zooming; separated 3D-2D viewFocus: interaction & vis. mapping; sacrifice render quality (no render styles or shadows; simple shading)DesignDemoSpecificsReflection
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One-man group, so feature sacrifices and priorities need to be made!!!3
Implementation ChoicesDev Environment: Linux; hence Cross-PlatformJava OpenGL (JOGL); no SceneGraph avail.Shaders in GLSLUI: SWT (native UI on each system)distribution via web (Java webstart) or binaryGraphing library: SWT charttryouts with modern OpenCL list sorts failed ...DesignDemoSpecificsReflection4
DemoDesignDemoSpecificsReflection
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Specifics non-implemented featuresFocus+Context via lensingswitch perspective/orthographic proj.Dataset comparisonGlyphing: limited by render speedProbability distribution function (PDF)Convolution kernelsDesignDemoSpecificsReflection6
CuberillesOpenGL 2: triangle array too slow (call-bound); blending problemsOpenGL 3: geometry shader reduces to point callsOpenGL 4: instanced rendering (not impl.)Geometry shader description of cube simple, spheres demand more callsCube: 6 triangle patchesSphere (6 vert., 12 horiz. resolution): 72 triangle p.DesignDemoSpecificsReflection7
CuberillesDesignDemoSpecificsReflection8
12 yo laptop, GLES: 64x64x29Lab PC, Quadro K4200, GL3: 512x512x232
Alpha CompositionProblem: Render-order dependent compositiondepth peeling => small number of alpha layerstried pre-computed render orders (1 per bounding box corner): didnt really work ...Sorting: just points, not cube verticesSimple view-dependent sorting not interactiveParallel sorting improved speed reasonablyDesignDemoSpecificsReflection9
Alpha Composition
DesignDemoSpecificsReflection10
common alpha composition with x-y-z render orderpre-computed, closest-corner render orderrender order computed each frame
Normal/Gradient VisualisationNormal: divergent per dimension & between positive/negative slope; defined 0-pointDesignDemoSpecificsReflection11
full colour spectrum ->colour-blind problemdivergent, too brightxy mapping+; z mapping -contrast-less; 0-value confusergood contrast, good highlights; confuser: N[0 0 1] = N[0 0 0]divergent between x-y-z:[magenta-blue-purple]
divergent to slope directionwith saturation:[high-mid-low] = [-1 0 1]
0-value confuser possible
V-1 = I-1
Geological DatasetsGeological facies datasets similar to CT (depict structure)statistical exploration can help to spot rock relationshipsDesignDemoSpecificsReflection12
porosity model depicts structure poorly
facies model depicts structure very well
Lessons learned ...Cubrilles: possible, but not advisable (modern GPUs do volume raycasting better)Statistics: helpful for exploring new datasetsLighting: highlights structure in volumes unexpectedly wellGPU sorting: did improved; still not comparable to CPUGradient/Normal Mapping: harder than it seems ...Volume Visualisation: its fun Lonely Rider not advisable a good team is better than the sum of its individuals ...
And: thank you for the time to update my OpenGL knowledge DesignDemoSpecificsReflection13
River Discharge
SANDSILTSearching for a summer orsemester job ?
Doing Volume Visualisationin Geology ?
then THIS may be for you!
Delft3D Delta Modelling: WebVis using WebGL / osgjs detailed, time-dependent, multi-variate VolumeVis teamwork with experienced 3D engineer as guide cool project, good team ... & getting in touch with petroleum
Contact: Simon J. [email protected]
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