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Real-time Screen-space Geometry Draping
for 3D Digital Terrain Models
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DEFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models H
Draping Process
Digital Surface/Elevation/Terrain Model: Draping Target (DT) DrapingcResult
Geometry: Draping Source (DS)
Projection of 2D/2.5D geometric features (lines, polygons) onto 2.5D/3D geometry.
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In GIS, features = polygonal data representing:
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models E
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DEFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models N
Golden Gate Bridge, Google Earth, version 7.1.2.2041
Street overlay does not match digital terrain model
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Problem: Different geometric representations:
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Major challenges:
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models X
Mismatch in correspondence and tessellation level
Feature is matching digital elevation model
Feature is matching 3D terrain model
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models Y
3D DTM Optimal Result Projective Texturing
Stencil-based Shadow VolumesGeometry Draping (Scene)
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Traditional approach based on projective texturing:
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Problems:
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models G
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Feature projection based on Shadow Volumes:
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Scene-space approach:
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Screen-space approach:
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models J
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DNFDGFHDIJ Real-:me Screen-space Geometry Draping for 3D Digital Terrain Models ID
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Geometric information for projecting geometry in image-space:
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G-Buffer
Normal + Z Color
3D Geometry
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models II
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Approach:
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Fitted Geometry Planar Geometry Normal + Z
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VI
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fetch z-value
DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models IH
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Final Image Projected Geometry Color Texture
DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models IE
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Test Data (DT):
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Test Hardware:
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Test Procedure :
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#VerKces #Triangels
Frames-per
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Second
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models IN
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Multi-pass hardware-accelerated tessellation of DS:
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models IX
Visualization of inner/outer
tessellation levels of OpenGL
tessellation shader API.
Pass 1 Pass 2 Pass 3
Pass 4 Pass 5 Pass 6
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Vi0
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DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models IY
Possible GPU-based approach:
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Visualization of inner/outer
tessellation levels of OpenGL
tessellation shader API.
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Possible GPU-based approach:
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3D Terrain Model
Street (z-level: 0)
Street (z-level: 1)
DNFDGFHDIJ Real-time Screen-space Geometry Draping for 3D Digital Terrain Models IG
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Overview of draping approaches presented
Interactive GPU-based rendering technique:
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DNFDGFHDIJ Real-:me Screen-space Geometry Draping for 3D Digital Terrain Models I_