ogic - manfred buchroithner - karst caves in tropical jungle: 3d mapping and generation of the...

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

manfred.buchroithner@tu-dresden.de

InDOGOlomouc 13 - 16 October 2014