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Visualization and Sharing of 3D Digital

Outcrop Models to Promote Open Science

Paul Ryan Nesbit, Adam D. Boulding, Christopher H. Hugenholtz, Dept. of Geography, University of Calgary, 2500 University Drive
NW, Calgary, Alberta T2N 1N4, Canada; Paul R. Durkin, Dept. of Geological Sciences, University of Manitoba, 66 Chancellors Circle,
Winnipeg, Manitoba, R3T 2N2, Canada; and Stephen M. Hubbard, Dept. of Geoscience, University of Calgary, 2500 University Drive
NW, Calgary, Alberta T2N 1N4, Canada

ABSTRACT INTRODUCTION opportunities to analyze and revisit data at
High-resolution 3D data sets, such as High-resolution 3D digital models are multiple scales. Open source programs,
digital outcrop models (DOMs), are increas- becoming increasingly common data sets in such as Blender and CloudCompare, can be
ingly being used by geoscientists to supple- academic and commercial applications. In used for data exploration and measurement
ment field observations and enable multi- the geosciences specifically, digital outcrop and have also integrated specific geosci-
scale and repeatable analysis that was models (DOMs), or virtual outcrops, can ence toolsets (e.g., Brodu and Lague, 2012;
previously difficult, if not impossible, to provide geoscientists with photorealistic Dewez et al., 2016; Thiele et al., 2017).
achieve using conventional methods. De- models that preserve spatial precision, Although acquiring DOMs has become
spite an increasing archive of DOMs driven dimensionality, and geometric relationships more straightforward, and various 3D analy-
by technological advances, the ability to between geologic features that are inherently sis programs are available, dissemination of
share and visualize these data sets remains 3D and susceptible to distortion and/or loss DOMs, interpretations, and results has
a challenge due to large file sizes and the of information when rendered in 2D (Bellian remained a challenge due to software and
need for specialized software. Together, et al., 2005; McCaffrey et al., 2005; Jones et file-size barriers. Specialty 3D programs are
these issues limit the open exchange of data al., 2009). Digital 3D mapping approaches often hindered by product licensing and can
sets and interpretations. To promote greater using DOMs have enabled geoscientists to involve a considerable learning curve to
data accessibility for a broad audience, perform supplemental measurements, corre- understand controls, file formats, and inte-
we implement three modern platforms for lations, and interpretations that are difficult grated tools. Furthermore, DOMs can easily
disseminating models and interpretations or impossible to obtain with traditional meth- exceed multiple gigabytes (GB) in size,
within an open science framework: Sketch- ods (Figs. 1–2; Pavlis and Mason, 2017; Nes- which can be taxing on computational
fab, potree, and Unity. Web-based plat- bit et al., 2018). resources for rendering, file storage, and
forms, such as Sketchfab and potree, render Until recently, however, collection and data transfer. With the growing collection of
interactive 3D models within standard use of digital data sets has been limited to high-resolution DOMs and similar 3D data
web browsers with limited functionality, specialists, due to hardware and software sets, there is a need for dedicated, intuitive,
whereas game engines, such as Unity, limitations. A number of methods are now and accessible 3D visualization platforms.
enable development of fully customizable available for collecting and processing 3D Given the challenges outlined above, we
3D visualizations compatible with multiple models (Hodgetts, 2013; Carrivick et al., examined existing visualization solutions
operating systems. We review the capabili- 2016). In particular, structure-from-motion that could potentially enable sharing of
ties of each platform using a DOM of an and multi-view stereo (SfM-MVS) photo- DOMs and support open science through
extensive outcrop exposure of Late Creta- grammetry software, commonly paired increased data accessibility. To provide a
ceous fluvial stratigraphy generated from with uninhabited aerial vehicles (UAVs), functional introduction to modern visualiza-
uninhabited aerial vehicle images. Each enables geoscientists to produce photoreal- tion platforms, we illustrate the capabilities
visualization platform provides end-users istic DOMs through a highly streamlined and functionality of two web-based inter-
with digital access and intuitive controls to UAV-SfM workflow (Chesley et al., 2017; faces (Sketchfab and potree) and a cross-
interact with large DOM data sets, without Nieminski and Graham, 2017; Pavlis and platform videogame engine (Unity) using a
the need for specialized software and hard- Mason, 2017; Nesbit and Hugenholtz, 2019). geologic case study. A DOM was produced
ware. We demonstrate a range of features Related efforts have centered on the through a UAV-SfM workflow for an exten-
and interface customizability that can be development of 3D software solutions with sive outcrop (1 km ) exposed within the bad-
2
created and suggest potential use cases tools for geoscience applications. Custom land landscape of Dinosaur Provincial Park
to share interpretations, reinforce student software packages, such as Virtual Reality (Alberta, Canada). Each visualization plat-
learning, and enhance scientific communi- Geology Studio (VRGS; Hodgetts et al., form provides access to the large DOM
cation through unique and accessible visu- 2007) and LIME (Buckley et al., 2019), through an intuitive lightweight interface
alization experiences. offer users lightweight executable tools and without the need for high-end hardware,

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