ReforestAR: An Augmented Reality Mobile Application for
Reforest Purposes
Matias Luna
, Enrico Gomes
, Alexandrino Gonçalves
1,2 a
, Nuno Rodrigues
1,2 b
Anabela Marto
1,2 c
and Rita Ascenso
1,2 d
School of Technology and Management, Polytechnic of Leiria, Leiria, Portugal
CIIC, ESTG, Polytechnic of Leiria, Leiria, Portugal
Keywords: Augmented Reality, Mobile Application, iOS, Android, Reforestation.
Abstract: Forest areas are essential to life on planet Earth and, without them, human society would not be able to sustain
itself. Yet, they are under constant threat of reduction and damage, and many of them have been lost
worldwide. Besides preventing their disforestation in the first place, awareness for maintaining, replanting,
and restoring these areas should be raised to live in a greener and healthier environment. Information in
modern times is mostly passed on through technology and, with the rise of Augmented Reality (AR), coupling
both smartphones (devices that most people use in current times) and nature seems like an opportunity to raise
consciousness to the cause. In this paper, we present an application to relate both Augmented Reality and
reforestation, to raise awareness of environmental damages by allowing users to virtually place 3D models of
trees on a real surface, using their own mobile phones, helping to plan and to visualize the replanting process
over previously destroyed areas.
Augmented Reality (AR) technology can be
perceived as an “enhanced” version of reality or, in
other terms, a mixture of a real-world environment
with virtual components such as interfaces and
objects overlaid on it. One of the technology trends
that have been growing more accessible every year,
AR is highly responsible for the successful user
experiences of the most downloaded applications in
the current market, such as online shopping catalogue
applications. Some of AR’s main uses and
functionalities are facial recognition, geolocation,
object recognition, and phone tracking.
Nowadays, AR continues to grow significantly and
new applications have been and are being developed.
While most AR apps are focused on the entertain-
ment or shopping industry; the mobile application
market can also be used for education, entertainment,
and others. AR is being increasingly selected to be used
to generate awareness in diverse areas, for example,
about past landscapes and endangered animals.
Context and Motivation
Deforestation is the process of removal of an area that
contains vegetation such as trees, shrubberies, and
plants. Normally these are natural areas reconditioned
for human activities such as agriculture, cattle raising,
and the creation of urban cities. According to the
magazine World Wildlife Fund
(WWF) (WWF -
Endangered Species Conservation | World Wildlife
Fund, 2021), 31% of the land is covered by forests,
and year by year the human footprint in the green
areas grows. The main activity that contributes to
deforestation is wildfires, being estimated that 94%
of it is caused by humans (e.g., lighting bonfires and
discarding cigarette butts). The other 6% are caused
by natural disasters such as earthquakes, thunder, and
hot temperatures during summer. This demonstrates
that, if human lapses are reduced, wildfires will too
(Deforestation and Forest Degradation | Threats |
WWF, 2019).
After a forest cover area is damaged or burnt by a
wildfire, a process of reforestation can be initiated to
World Wildlife Fund is a sixty-year-old conservation
organization that works helping local communities
conserve the natural resources in nearly 100 countries.
Luna, M., Gomes, E., Gonçalves, A., Rodrigues, N., Marto, A. and Ascenso, R.
ReforestAR: An Augmented Reality Mobile Application for Reforest Purposes.
DOI: 10.5220/0010833200003124
In Proceedings of the 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP 2022) - Volume 1: GRAPP, pages
ISBN: 978-989-758-555-5; ISSN: 2184-4321
2022 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
recover from damages. A reforestation process can be
defined as naturally or artificially, by replenishing an
area that has been deforested with trees and plants
(Reforestation, 2021), and it happens when there is a
public or private interest in recovering that area due
to its ecological, social, or production value.
In this study, an application is proposed to join both
AR and reforestation to raise awareness of
environmental damages. By immersing users into a
real-time reforestation experience, the objective is to
allow users to virtually place 3D models of trees onto
real-world surfaces, by use of smartphones, in both
iOS and Android platforms.
The application, named “ReforestAR”, lets users
place virtual trees on detected surfaces, and with this,
simulate a reforestation planning experience. This
behaviour was achieved by the usage of an algorithm
that acknowledges the minimum distance between
trees. The application also enables users to
personalize the experience with specific options such
as scale modification, the quantity of placed trees, and
the type of tree that is being placed. Saving, loading,
and sharing reforestation projects are also possible.
Research of available published apps and an
extensive scientific review was accomplished to
better comprehend the current state of AR in the
market, considering its features, user interface and
main functionalities.
2.1 Available Published Apps
The market available apps related to reforestation
provide some interesting features related to the topic.
For example: Reforest App offers the possibility to
control the carbon footprint that humans emit with
their day-by-day activities (Reforest - Restore the
planet and reverse climate change, 2021), or Replant
(REPlant, 2015), whose main goal is to create a plants
lover’s community in Brazil, by dynamic
dissemination of stores, fairs, forums and events
related to reforestation.
An example of the integration of AR technology
with mobile apps is found in the Reforestation of the
Imagination (RIT) (Reforestation of the Imagination,
2011), an AR application developed in Unity
the Vuforia
framework. The application recognized
tree rings of sculptures in an art exhibition and show
a 3D model of the tree.
Journals and entities have started to create their
own AR apps, for example, The TIME
mobile application (Introducing TIME Immersive, a
New Way to Experience TIME's Journalism, 2019)
was developed by an American news portal. Within the
application, the user can experience immersive AR
experiences (Example: simulation of deforestation in
the Amazon Forest). Another example is the official
mobile application of the World Wildlife Fund
(Introducing WWF Forests, now live in Apple's App
Store, 2021) that uses AR technology to show the user
species of flora and fauna of native forests, even with
real sounds and interaction features.
In the addition to the available apps in the market
analysed, it is also important to know what scientific
studies have been realized in the field of reforestation
with this technology in recent years.
2.2 Scientific Review
A mobile application using AR technology for plant
recognition was implemented by students at the
Technological Institute of the Philippines. It has
information on about twenty-five kinds of herbal
plants that can be found in the Philippines. The AR
feature allows users to scan an image of a plant
through the device’s camera, it is recognized and, if it
is one of the included plants of the database, the 3D
object of the plant is created and shown on the screen.
When the figure is tapped, information about the
species is presented. The authors evaluated
suitability, accuracy, learnability, operability, time
behaviour, resource utilization, and recoverability of
the application by getting users’ feedback. Thirty
answers resulted in a medium grade of 4,29 out of 5.
The application was considered as “acceptable”
according to the parameters that were evaluated
(Angeles, 2017).
Another mobile application that uses AR
technology for plant tracking and modelling was
developed by researchers of the Central China
Normal University in Wuhan, China in 2019. The
Unity is a cross-platform game engine with its own IDE.
Vuforia is an open-source SDK for creating AR
TIME refers to the American news magazine.
ReforestAR: An Augmented Reality Mobile Application for Reforest Purposes
application’s main objective was to help people gain
interest in plant learning. The application workflow
starts with the user taking picture of all 360 angles of
the plant with the device’s camera. Then, the Vuforia
engine obtains information about the tracking object
and generates a similar 3D model, that will be shown
on the screen after a user tap. For future work, authors
promote the usage of recent technologies to create
new interactive, interesting, and imaginative ways of
learning (Zhao, 2019).
In 2019, researchers from the University Carlos
III of Madrid created a game that uses the Internet of
Things (IoT), Ubiquitous Computing (UC), and AR
technology to simulate a virtual representation of the
process of planting and gardening. It is called “The
Magic Flowerpot”, and the principal objective of the
game is to encourage people to learn about vegetation
in their local environment. The authors stated that the
game work is divided into three phases: 1) taking
pictures of the plants that the users aim to grow in
their virtual garden, 2) the user “virtually seeds” the
virtual plant with the help of the mobile application
on a unique location called, the “Augmented Smart
Pot and awaits for its growing, 3) using the
application the plant can be placed to any spot, and
the “Augmented Smart Pot” can be reused for more
seeds. Eventually, the user will have a virtual garden.
The authors expect their work to serve as an example
of the usage of the IoT, UC, and AR technologies
integrating virtual and real environments for learning
purposes (Zarraonandia, 2019).
The process of planning and development of both
mobile applications iOS and Android followed the
agile development methodology, allowing
the authors to make a progressive series of
incremental upgrades over time when adding,
updating, and removing features.
Currently, the Portuguese mobile market is ruled
by two operating systems (OS): Android by Google
and iOS by Apple
(Mobile Operating System Market
Scrum is one of the most used agile development
Google refers to the American multinational
technology company.
Apple refers to the American multinational technology
Share Portugal | StatCounter Global Stats, 2021).
Since the main goal is to reach the largest number of
people, the application was developed for both OS.
The application interacts with different components
to work correctly. Figure 1 displays a detailed
overview of how the interaction and communication
between the back office and Cloud services of
with both iOS and Android operates.
Figure 1: Integration between agents and components.
Data from users of both OS are kept in the cloud,
through Google’s NoSQL
Realtime Database,
Firebase. Its structure follows a JSON (JavaScript
Object Notation) tree, which is optimized for quick
operations that enhance the responsiveness of a real-
time experience.
The application has three 3D models available for
the user to place in the AR reforestation scene for
study purposes, but it has information relative to
seventeen species of trees that are native in Portugal.
Even though Vuforia AR SDK is one of the most
popular choices for an AR SDK, ARKit
were chosen instead, due to their native
compatibility and for presenting no limitations in
their use (no watermark or commercial restrictions).
3.1 ReforestAR Architecture
Figure 2 shows the navigation bar from where the
user can switch between five sections: Areas,
Projects, ReforestAR, Catalog, and User.
Google’s Firebase platform to create mobile and web
NoSQL databases store data differently than relational
tables, having a variety of types such as document, key-
value, wide-column, and graph.
ARKit is Apple’s SDK that developers use to create AR
mobile applications.
ARCore is Google’s SDK that allows developers to
create mobile applications with AR features.
GRAPP 2022 - 17th International Conference on Computer Graphics Theory and Applications
The Areas section shows the map with the
device’s location, where overlaid polygons represent
the predefined areas that the system has defined.
Figure 2: iOS General View Architecture.
The Projects section shows a list of all the
reforestation projects associated with the
authenticated user. When adding a virtual 3D tree
model with AR, its placement is associated with a
project. Each project has a specific view that is shown
when selected from the list, showing the project’s
name, description, status, number of trees, associated
users, and sharing/deleting functions if the user that is
accessing the page is the project owner.
The Trees section shows a list of all the tree
species considered in the project’s scope. A specific
view of each tree is shown when selected, and it
shows the tree’s Latin name, common name,
recommended space between each one when planted,
its minimum and maximum height, and a description.
The User section shows the user’s name, email,
username, statistics about the number of projects of
the authenticated user, and the number of planted
trees. The login, logout and account registration
options are also available here. All registration and
login forms have validation functions and error
messages when invalid information is inserted.
The ReforestAR section holds the AR view where
the main features of the application are available, or
in other words, the AR camera.
3.2 ReforestAR Placement Algorithm
When the user taps on an available horizontal surface
on the screen, an object is created in that position. The
algorithm was created so when the user taps to create
objects, it must respect some ground rules as if it was
a real reforestation plan. The user can’t create an
object in a position where there is another virtual
object. Every object should have a distance value to
prevent this from happening. Now, when the user
intends to create more than one object with a single
click, the first object will be placed in this position,
but it will also be used as the origin position to create
new random positions for the new objects that are part
of the same tap group. The new positions will go
through several comparisons that will verify that they
are valid positions to simulate a reforestation
environment. If the positions created do not comply,
a new position is created and the verifications are
made again, having a limit of twenty attempts per
position, before failing and communicating to the
user that the place where they intend to place the
objects does not have enough space.
The three rules that the new random positions
must follow are: 1) To be between a “min_distance”
and “max_distance” away from the initial position,
i.e., the first tap of the user. 2) To be “min_distance”
and “max_distance” away from any of the models
from the same tap group. 3) To be “min_distance”
and “max_distance” away from any models that
already existed in the scene before the tap group. The
process is depicted in Figure 3.
Figure 3: Algorithm implementation, rules visualization.
3.2.1 Algorithm Load Functionality
The process of loading is activated once the user taps
in the button, and it will retrieve the information
about stored 3D models in the selected project. Then,
the placement of these models in the AR environment
works differently on each OS. In iOS, the user will
select a point in the surface that will serve as the
origin position to relate the stored 3D models
previous positions. In Android, the initial tap is not
necessary since the origin position is calculated
automatically, so the objects are placed once the load
function is finished.
ReforestAR: An Augmented Reality Mobile Application for Reforest Purposes
3.3 Limitations
3D models with a size of more than 200MB were
excluded since pilot tests concluded that they were
not appropriate for the test device RAM capacity.
Apple’s Scene Kit 3D object format “Universal
Scene Description” USDZ keeps all the assets of the
AR Scenario (including the 3D object) as a folder
structure of nested sub-elements from a single “zip
file”, but when 3D objects were imported to Apple’s
Scene, some of their features were not correctly
applied to the exported 3D object, as perceived in
Figure 4. That is why the same models in iOS look
different from Android.
Figure 4: Views of both ReforestAR application layout.
Another limitation to consider is that, since the
applications were not developed in a unified
environment, some elements were implemented
differently in each platform according to the available
native components of each OS. A greater focus was
given to the academic context of the application and
functionalities in iOS instead of layout elements.
3.4 iOS Application
The used software to develop the ReforestAR
includes Foundation (the base framework of all
classes), UIKit and SwiftUI for UI design,
MapKit and CoreLocation for map and location
services, AR Kit, Reality Kit and Scene Kit for AR
features, and the Firebase iOS SDK for integration
with database.
ReforestAR Section in iOS was developed with
SwiftUI and it is compound by different buttons,
labels, sliders, switchers, and pickers with each one
of them with a specific function.
Some of the views have either SwiftUI, UIKit
components, or both. The way of communicating the
changes happening in SwiftUI components to UIKit
Swift is the programming language developed by Apple
used to create applications for Apple devices.
components is done with the API of the Notification
and redundancy of variables. SwiftUI
components are reactive, so the variables state is kept
through the application cycle and it is evident in the
user’s screen.
Labels that show relevant information, such as the
current number of trees that have been placed in the
current session and the real-time geographic location
of the user's device, were added. A toggle switch
activates a functionality that compares the current
user’s device location to the one stored in the project
once the load functionality is triggered. Buttons to
remove the last placed tree from the current session,
present a view with all available models that may be
selected, and display or hide a right bar menu. This
right bar menu contains a picker selection for
configuring the number of trees to be placed by a
single tap (from 1 to 10), a slider that modifies the
scale of future placement models, and another button
to display or hide a small menu that includes features
to delete all the placed trees existing in the current
session, select the associated project, and save and
load progress from the associated project.
3.5 Android Application
The AR camera interface and functionality in
Android operate with minor differences from the iOS
version. When the section is selected (or when
initially loaded, being the application home page), a
user instruction guide is presented to elucidate the AR
camera process and application navigation. At the end
of the instructions, a button with a camera icon is
provided and it is responsible for opening the AR
camera. When it is opened, a process of calibration
starts and the camera needs to recognize the
horizontal surface on which trees will be placed. This
is achieved by circularly moving the phone around
and it is complemented by an animation overlayed on
the screen representing the necessary movement to
help guide the user. Once the surface is detected, an
area with white spots will be shown in the AR
environment displaying the exact area where tree
placement is available.
A menu panel can be toggled by tapping on the
bottom right corner button. This menu has many
actions and settable parameters accessible to the user,
those being: action options for saving a project,
undoing the last tree placement, deleting all placed
trees; selecting the type of 3D tree model (species) to
Notification Centre is a notification dispatch mechanism
of Swift that helps with communication within the
GRAPP 2022 - 17th International Conference on Computer Graphics Theory and Applications
be planted; selecting the height of the next tree to be
planted; and, finally, selecting the number of trees to
be planted at once. This interface can be seen in
Figure 5.
Figure 5: Android ReforestAR AR view.
Differing to ReforestAR for iOS, in Android, the
load function is triggered from the Projects Section
(not from the AR Section) and when the save option is
selected, a dialogue confirmation box is shown asking
for the project name and the project description to
associate the 3D models’ placements disposition
(positions in the AR environment) to be saved.
This section contains an assessment of the proposed
architecture, the apps developed for this study and the
existing available apps and published scientific work.
4.1 Comparison with Published Apps
After the analysis of similar published applications, a
comparison between each application features was
conducted, as can be seen in The comparative board
includes information about six applications, five of
them previously analysed and the last being the
study’s proposed application.
The comparative board includes information
about six applications, five of them previously
analysed and the last being the study’s proposed
ReforestAR, like some of the other contemporary
apps, has support for iOS and Android. It includes a
feature to create and place 3D objects of trees through
AR as the other two applications do but has no carbon
footprint control and no 3D object recognition as
there were no planned requirements that would utilize
these features.
Table 1: Differences of ReforestAR to other applications.
4.2 Comparison with Scientific Work
After a summary of the exposed ideas from scientific
studies in reforestation and AR technology, a
discussion about the differences that ReforestAR
provides was made.
All the analysed studies had mobile apps
developed with Unity using the Vuforia SDK, and
two of them confirmed their support for Android
devices. What this shows, is that there is a preference
for the usage of this software for AR apps for Android
OS. Nonetheless, when analysing the published apps,
most of them included a version for iOS, something
that ReforestAR has also done to reach a large
number of users. Two of the analysed studies’
applications allowed user interaction with the 3D
object, while in ReforestAR object interaction is not
allowed. None of the previously analysed studies had
the functionality to create more than one 3D object at
the same time and ReforestAR does allow it.
The main purpose of all the analysed apps was
educational, with a focus on the improvement of the
learning of plants and environmental awareness with
an interactive alternative for support, much in line
with one of the main goals of this project.
Following the expected pipeline of interface
development, informal tests were conducted with
different individuals to correct possible errors and
improve user experience. Notwithstanding, at the end
of the application development procedure, the System
Usability Scale (SUS) questionnaire was applied to
obtain a usability score for our application from a
group of users that volunteered to test them. The SUS
questionnaire contains ten statements that can be
scored from 1 to 5, where 1 stands for “Strongly
disagree” and 5 for “Strongly agree” (Assistant
Secretary for Public Affairs, 2021).
ReforestAR: An Augmented Reality Mobile Application for Reforest Purposes
The number of users available for testing varied
for each platform and can be considered a small
quantity (this is due to the current global pandemic
COVID-19), as iOS had four test participants and
Android, seven. However, results were useful for the
analysis of the usability of the application and future
work considerations, even if on a modest scale. Each
participant was also informed about the context of the
study, the purpose, and the goals that the development
of this project attempted to accomplish, thus causing
a positive reception in all of them, mostly due to the
apps’ environmental component.
5.1 Test and Results for iOS
Tests on iOS and iPadOS were conducted. The users
could use their mobile devices to experiment the
application. The SUS forms were answered in the
English language. Participants tested the application
indoors and outdoors for ten minutes approximately.
In Figure 6, all scores of each question by every
participant for the iOS and iPadOS is shown.
Figure 6: Each question's score by iOS user tests.
The average SUS score of all four participants was
72.5 on a scale between 0 and 100. All participants
had an age interval between twenty and thirty years
old. Statistically conclusions cannot be done because
there were not enough participants, but participants
related to the environmental cause were more
interested in the study. After being inquired about the
operation of the application, answers show that the
application’s interface was simple to operate,
highlighting that the most difficult part to interact
with, was using the ReforestAR section.
5.2 Test and Results for Android
As previously stated, due to the global pandemic
situation, the number of users that could test this
platform were limited, seven to be precise. Four tests
were realized by compiling the application on a
Samsung A40 device.
The test users were characterized into two age
groups, one being “between eighteen and nineteen”
and the other, “between fifty-four and sixty-one”,
with two members in the first group and two members
in the second. Members of the second group did not
have previous experience with AR.
Another round of tests, this time realized on a
Samsung Galaxy S5e 10.5” tablet, was also realized
with three participants, all in the age category of
“between eighteen and twenty-nine”. Navigating and
operating the application this time was easier for the
participants, presumably due to better hardware
specifications of the device used for testing.
After testing the application, participants were
asked to answer the SUS questionnaire. The average
SUS score of the first age group was 78.5, considered
“Good”, and for the second one, 84, also considered
“Good” in adjective ratings (Bangor, 2009). Figure 7
demonstrates each question’s score by a participant.
After being inquired about the ease of navigation
and operation of the application, most participants
stated that they thought the interface was very simple
to operate and that the most difficult part of the
operation was when using the AR camera but agreed
that most people would learn to use this system very
Figure 7: Each question's score by Android user tests.
This study had the purpose of developing mobile
applications, both for iOS and Android platforms, that
could assist users to experience what reforesting trees
could look like, and beyond the successful
development, there were satisfactory user tests. The
concise feedback received from these tests showed
that all the users that operated the applications found
them accessible and easy to use, despite a need for an
initial short learning time.
Question number
Question number
GRAPP 2022 - 17th International Conference on Computer Graphics Theory and Applications
The difference in the general score for both apps
may be attributed to differences in layout and
possibly due to the Android application having
instructions on how to operate it. This might indicate
that instructions are vital for a better user experience.
The authors intend that ReforestAR for iOS and
Android can assist in reforesting lost areas with its
planning capabilities and become widely used.
Considering that this application is at an initial
proposal state, future work on this project is
contemplatable. It can include saving and loading 3D
models according to geolocation placement values,
more configuration parameters for the AR camera
interface, a more realistic placement algorithm that
considers each species’ minimum placement
distances, a carbon footprint calculator for projects
according to the number of trees, and a tutorial view
for the iOS platform.
Hopefully, when ReforestAR becomes available
to the general public, the interactive experience of
planting virtual trees can bring their attention to the
topic of deforestation and reforestation, and
consequently, raise awareness of these sensitive
Since real-world reforestation projects tend to
have visible results only after a couple of years, we
believe that the immediate nature of viewing a tree in
a deforested zone through ReforestAR can help
motivate users to this subject.
This work was supported by national funds through
the Portuguese Foundation for Science and
Technology (FCT) under the project
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ReforestAR: An Augmented Reality Mobile Application for Reforest Purposes