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Bachelor's Thesis
Author of thesis: Pavel Hájek
Acad. year: 2025/2026
Supervisor: Ing. Dávid Pukanec
Reviewer: Ing. Tibor Kubík
This thesis focuses on surface reconstruction from 3D point clouds using deep learning. Specifically, it reimplements a method called Implicit Filtering, which uses a neural network to learn a signed distance function and a nonlinear filter to preserve sharp geometric details such as edges and corners. The reimplementation is verified to produce results comparable to the original method on two datasets: ShapeNetCore and ABC. Further experiments examine how the method behaves under noisy input, missing regions, and variations in network architecture. The results show that mild noise can actually improve reconstruction quality for complex shapes, while severe noise and large missing regions consistently degrade performance. Larger networks work better for complex, densely sampled shapes, while simpler shapes benefit from smaller networks. Finally, while dynamic loss weighting showed no significant effect, augmented query point sampling led to slight improvements for simpler models. However, combining both optimization approaches resulted in a slight performance degradation.
Surface reconstruction, point cloud, signed distance function, neural network, implicit filtering, overfitting, deep learning
Date of defence
16.06.2026
Result of the defence
Defended (thesis was successfully defended)
Grading
C
Process of defence
Student nejprve prezentoval výsledky, kterých dosáhl v rámci své práce. Komise se poté seznámila s hodnocením vedoucího a posudkem oponenta práce. Student následně odpověděl na otázku oponenta a na další otázky přítomných. Komise se na základě posudku oponenta, hodnocení vedoucího, přednesené prezentace a odpovědí studenta na položené otázky rozhodla práci hodnotit stupněm C.
Topics for thesis defence
Language of thesis
English
Faculty
Fakulta informačních technologií
Department
Department of Computer Graphics and Multimedia
Study programme
Information Technology (BIT)
Composition of Committee
doc. Ing. Lukáš Burget, Ph.D. (předseda) doc. Mgr. Adam Rogalewicz, Ph.D. (místopředseda) Ing. Libor Polčák, Ph.D. (člen) Ing. Michal Hradiš, Ph.D. (člen) Ing. Martin Žádník, Ph.D. (člen)
Supervisor’s reportIng. Dávid Pukanec
Pán Hájek si osvojil ťažšiu problematiku rekonštrukcie povrchu z mračna bodov pomocou hlbokého učenia. Študent si naštudoval súčasnú odbornú literatúru a sám si vybral metódu, ktorú následne implementoval a otestoval na sade experimentov so zaujímavými výsledkami. Dokázal tým svoju zdatnosť v spracovaní 3D dát, ako aj v implementácii a učení neurónových sietí.
Zadanie práce bolo zamerané na oboznámenie sa s neurónovými sieťami určenými na spracovanie 3D dát. Študent si musel dôkladne naštudovať aktuálne metódy v danej oblasti, ako aj vybrať vhodný dataset na otestovanie funkčnosti riešenia. Z tohto hľadiska hodnotím zadanie ako náročné v kontexte bakalárskej práce .Študent vykonal sadu experimentov, v ktorých ukázal, ako sa metóda správa v rôznych nastaveniach, a ukázal, ako možno dosiahnuť lepšie výsledky.
Študent si samostatne vyhľadal relevantné zdroje a moderné metódy týkajúce sa danej problematiky. Dokázal úspešne naštudovať odbornú literatúru, rýchlo sa zorientovať v riešenom probléme a získané poznatky následne aplikovať vo svojej práci.
Práca bola konzultovaná v pravidelných intervaloch a na konzultácie chodil dostatočne pripravený. Študent na konzultáciách ukazoval nové zistenia, ako aj problémy, ktoré práve riešil.
Práca bola vypracovaná postupne počas celého roka a bola dokončená v stanovenom termíne s prekonzultovaným obsahom.
Nie som si vedomý publikačnej činnosti.
Grade proposed by supervisor: A
Reviewer’s reportIng. Tibor Kubík
The student demonstrated the ability to work with a recent and technically demanding method for surface reconstruction from point clouds. The student re-implemented and optimized the selected method, verified it against the original results, and extended the evaluation with additional experiments. The thesis is clearly written, and the results are presented in a well-structured way, supported by appropriate visualizations, graphs, and tables. Some smaller weaknesses remain, mainly in the discussion of certain experimental factors and in the need for a more rigorous evaluation of the practical benefits of the new implementation. Nevertheless, considering the complexity of the method and the quality of the experimental work, I evaluate the thesis positively.
Evaluation level: obtížnější zadání
The aim of this thesis is to re-implement, evaluate, and extend the experiments of a very recent study on surface reconstruction from 3D point clouds using implicit neural representations. In order to do this properly, the student had to understand several recent research concepts in this area. Although a reference implementation and public datasets were available, I consider the assignment to be more difficult due to the complexity of the chosen method, especially at the bachelor’s student level.
The technical report presented by the student is easy to read, and the author communicates the goals and results of the thesis clearly.
The reader is first introduced to classical surface reconstruction methods, as well as to common artifacts that may occur in input point clouds. The author then presents several approaches to machine-learning-based surface reconstruction. The selection of publications is relevant, and their description is handled well. I consider Section 2.4, which introduces the basics of neural networks, to be somewhat less necessary. If such a section is included, it should either provide a more systematic overview or be more clearly focused on concepts directly needed for the thesis. In its current form, it discusses only selected aspects of neural networks, such as activation functions, convolutional networks, and encoder-decoder architectures, without making fully clear why exactly these topics were chosen and placed at the same level of importance.
The selected method is described in a dedicated chapter, which I find appropriate. The explanation is sufficiently detailed and easy to follow.
The implementation and experimental details are communicated well. The results are presented using clear 3D visualizations, as well as suitable graphs and tables where appropriate.
The typographic and language quality of the thesis is very good. The text contains only a minimal number of typos and is written in good technical English.
The work resulted in two main outputs. The first is a set of Python scripts implementing an optimized version of the I-Filtering framework for surface reconstruction from point clouds, including data preparation, training, and evaluation. The second main output is the set of experimental results presented in the technical report, including verification against the results of the original solution as well as additional custom experiments. The experiment studying sensitivity to model capacity would be more informative if it were more clearly separated whether the observed behaviour is caused by the complexity of the model itself or by the different number of sampled points across datasets.
The experimental results provide new insights into the I-Filtering method, for example, which is valuable for the research community.
Regarding the usability of the student’s new implementation, I believe that the work was certainly valuable from an educational perspective, as the student clearly had to gain a deep understanding of the method and the related problem area. The practical usefulness of the new implementation for the broader community would require further evaluation. For example, changes such as moving CPU-based acceleration structures to the GPU should be rigorously benchmarked to show whether they improve efficiency. This is, however, only a minor remark, since the primary output of the thesis is the experimental evaluation mentioned above.
Evaluation level: zadání splněno
The assignment has been fulfilled. The student provided an overview of suitable deep learning methods for the target task and selected a relevant recent approach. The chosen method was implemented by the student, optimized, and rigorously evaluated using both the original experiments and additional experiments defined by the student.
Evaluation level: je v obvyklém rozmezí
The length of the technical report is within the expected range.
The work contains a good number of high-quality references. Some references are cited as arXiv preprints, even though peer-reviewed versions are available. In addition, some web sources are not cited completely, as they do not include access dates.
Grade proposed by reviewer: B
Responsibility: Mgr. et Mgr. Hana Odstrčilová