Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Karst caves in tropical jungle: 3D mapping and generation of the biggest virtual cave model worldwide
Manfred F. Buchroithner & Benjamin Schröter
TU Dresden, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
InDOGOlomouc 13 - 16 October 2014
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Gomantong Caves – General Information
• Cave system on Borneo island,
Southeast Asia
• 30 km south of Sandakan, Malaysia
• Part of Sabah Parks Forest Reserve
• Gomantong Hill:
huge limestone formations
• Tourist attraction
• Economically important: bird’s nests
(sold as Chinese delicacy)
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
© Keith Christenson
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TU Dresden, 10.04.23 Präsentationsname XYZ Folie 13 von XYZ
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
© Keith Christenson
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
© Keith Christenson
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
© Keith Christenson
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TU Dresden, 10.04.23 Präsentationsname XYZ Folie 47 von XYZ
Gomantong Caves - Structure
Simud Hitam= Black cave
Simud Putih= White cave
Major entrance
32
2 m
ete
rs
330 meters
• Main entrance• Ceiling up to
90 m high• Parly open to
public• Walkway
• Entrance 90 m above Black cave
• Not open to public
• Still not fully explored
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Laserscanning of the Cave System
• Equipment:
• 2012: Faro Focus 3D S 120
2014: Faro Focus 3D X330
• 244000 points/second
• 121 scans performed
• 5.3 billion points totally
• 21 gigabytes raw data
• 8500 scanner-taken colour photos
all only in 2012; 2014 even more
• GPS reference points to combine
with aerial imagery
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Using UAV to Discover Gomantong Hill
• Need for high-resolution imagery instead existing 30 m resolution ASTER
dataset
• Equipment: Trimble Gatewing X100 autonomous drone
• Wingspan of 100 cm, easy to transport
• Flying at 400 m elevation
• 240 overlapping images with ~ 6 cm geometric resolution
• Covering complete Gomantong Hill: approx. 2.1 km2
• GPS control points taken using a Trimble GeoXH 600 and Trimble NetR9 base
station
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TU Dresden, 10.04.23 Präsentationsname XYZ Folie 50 von XYZThe Gatewing X100 drone
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Data Processing and Video Creation
TLS pointcloudsRegistration of pointclouds
Creation of 3D vrml terrain
Meshing a 3D geometry
Texturing
Aerial raw dataReferencing and mosaicing a DSM
Render video
FARO SCENE Geomagic Studio
MeshLab
Gatewing Stretchout
VTBuilder CINEMA 4D
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TLS Data Processing – Point Cloud Registration
• 121 single scanfiles need to know their position among each other
• Registration with FARO SCENE using reference spheres placed in the caves
• Colorization, subsampling, export as .vrml file
Raw pointcloud After applying image textures
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TLS Data Processing – Meshing and Texturing
Meshing: Geomagic Studio
• Preprocessing: noise reduction, outlier removal
• 121 million points polygons
• Cleaning, filling holes
Texturing: MeshLab
• Geometry + better resolved pointcloud model with *.jpg texture ready for
3D studio
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TU Dresden, 10.04.23 Präsentationsname XYZ Folie 54 von XYZ
Part of the 3D cave model, including separately modeled walkway
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Aerial Data Processing
• Software: Gatewing Stretchout
• Converts X100 image data to accurate orthophotos and DSMs
• Dataset contains 240 original images, 227 were used
• Georeferencing with 6 Ground Control Points (GCP) geotiff
• Converting into vrml 3D geometry using free VTBuilder + Geomagic Studio
Ortho Mosaic Digital Surface Model (DSM)
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TU Dresden, 10.04.23 Präsentationsname XYZ Folie 56 von XYZExported 3D geometry (*.wrl ready to use in every 3D studio)
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
TU Dresden, 10.04.23 Präsentationsname XYZ Folie 57 von XYZ
• Scientific analyses (speleologic, geologic, hydrologic, volume estimation…)
• Nest-bat counting algorithm automated procedure
• Visualization: Video
TLS & UAV data combined
(8550 frames, 5:42 min)
Application of 3D Model
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
National Geographic: Gomantong 2012(Guy van Rentergem)
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Virtual Flight – Gomantong(Stefan Hautz)
Faculty of Environmental Sciences, Department of Geosciences, Institute for Cartography
Thank you for your attention!
Manfred F. Buchroithner & Benjamin Schröter
InDOGOlomouc 13 - 16 October 2014