Pre-Integrated Volume-Rendering with Randomized Transfer-Functions Pre-Integrated Volume-Rendering with Randomized Transfer-Functions V3D2 Symposium 21./22. Februar 2002 Klaus Engel, Guido Reina, Thomas Ertl Abteilung Visualisierung und Interaktive Systeme Universität Stuttgart Klaus Engel, Guido Reina, Thomas Ertl Abteilung Visualisierung und Interaktive Systeme Universität Stuttgart Frank Oellien, W.D. Ihlenfeldt Computer Chemie Centrum Universität Erlangen-Nürnberg Frank Oellien, W.D. Ihlenfeldt Computer Chemie Centrum Universität Erlangen-Nürnberg
Transcript
Pre-Integrated Volume-Renderingwith
Randomized Transfer-Functions
Pre-Integrated Volume-Renderingwith
Randomized Transfer-Functions
V3D2 Symposium 21./22. Februar 2002
Klaus Engel, Guido Reina, Thomas ErtlAbteilung Visualisierung und Interaktive SystemeUniversität Stuttgart
Klaus Engel, Guido Reina, Thomas ErtlAbteilung Visualisierung und Interaktive SystemeUniversität Stuttgart
Frank Oellien, W.D. IhlenfeldtComputer Chemie Centrum Universität Erlangen-Nürnberg
Frank Oellien, W.D. IhlenfeldtComputer Chemie Centrum Universität Erlangen-Nürnberg
V3D2 Symposium 2002 - ChemVis Project
Volume Data Sources
Measurements (cryo-electron
microscopy)
Synthetic data(radial distance volume
+ Perlin Noise)
Binning ofmulti-variate data
Computed data(molecular orbitals)
Simulations (convection flow)
V3D2 Symposium 2002 - ChemVis Project
Volume Rendering - Physical Model
• Physics of light transport• Simplified to Volume Rendering Integral
• Transfer Function:Assigns opacity and color
• Discretization
•
0s
s
�� =⋅+= −−2
10
0 )(),(')'()()( 21),'(),(
0
s
s
s
s
ssss dssssdsesqesIsI κτττ
nss ���1
� ∏= +=
−=n
i
n
ijjiin CsI
0 1
)1()( αα
d d d d
V3D2 Symposium 2002 - ChemVis Project
Texture-based Volume Rendering
2D textures(axis-aligned
slices)
3D textures(view-aligned
Slices)
texturing(trilinear
interpolation)
texturing(trilinear
interpolation)compositing(blending)
compositing(blending)
texturing(bilinear
interpolation)
texturing(bilinear
interpolation)compositing(blending)
compositing(blending)
V3D2 Symposium 2002 - ChemVis Project
Volume Rendering - Classification
Voxel
Interpolation
Pre-Classification
Classification
Transfer-Functions
Post-Classification
Interpolation Classification
V3D2 Symposium 2002 - ChemVis Project
Higher Sampling Rates
Cryoelectron-microscopic VolumeIsosurface of Escherichia Coli Ribosome at 18 Ångström
All data slices 10 times more slices
V3D2 Symposium 2002 - ChemVis Project
Higher Sampling Rates – Problem
• Discrete Approximation of Volume Rendering Integral will converge to correct result for d→0– According to Sampling Theorem sampling rate must be
greater than the Nyquist frequency– But: High frequencies in the Transfer Function may
considerably increase the required sampling rate
• Pre-Integrated Volume Rendering– Idea: Split numerical integration into
• one pre-integration for the transfer function• one integration for the scalar field
– Pre-Integrate Ray-Segments in a pre-processing step
hardware-accelerated implementation on NVidia NV20and ATI R200
chips
project slice
sf sb
front slice
back slice
texture polygon
V3D2 Symposium 2002 - ChemVis Project
Single Peaked Transfer-Functions
V3D2 Symposium 2002 - ChemVis Project
Multi-Peak Transfer-Functions
V3D2 Symposium 2002 - ChemVis Project
Randomized Transfer-Functions
V3D2 Symposium 2002 - ChemVis Project
Randomized Transfer-Functions
V3D2 Symposium 2002 - ChemVis Project
Results – Classification schemes
Pre-Classification
Post-Classification
Pre-Integrated-Classification
V3D2 Symposium 2002 - ChemVis Project
Results - OrbVis
V3D2 Symposium 2002 - ChemVis Project
Results – Randomized Transfer Functions
V3D2 Symposium 2002 - ChemVis Project
Results – Randomized Transfer Functions
V3D2 Symposium 2002 - ChemVis Project
Results – Randomized Transfer Functions
V3D2 Symposium 2002 - ChemVis Project
Conclusions
• Pre-Integrated Volume Rendering– hardware-accelerated Implementation– integration into digital documents ?– reproduces high frequencies in the TFs– ideally suited for random TFs
• Randomized Transfer Functions– a new visualization technique for volume data– somehow related to LIC– visualizes “all” isosurfaces at the same time
V3D2 Symposium 2002 - ChemVis Project
InfoVis - Previous Work
VRML-based NCI Database Interface
substructuresearch
NCI anti-viral
anti-tumordatabase
detailedstructure
information
toxicity (LD50) of chemical compounds against breast
cancer cell lines
results
V3D2 Symposium 2002 - ChemVis Project
Current Work
InfVis Applet ITool Panel
(filters, selection
tools, details)
Java3DCanvas
ControlPanel
+Glyph-based(details)
volumetric(overview)
V3D2 Symposium 2002 - ChemVis Project
Future Worker
Guido Reina: „Visualisierung und Manipulation großer Graphenin einem Graphical User Interface am Beispiel der zSeriesI/O-Topologie”
