header

Publications


 

High-Fidelity Point-Based Rendering of Large-Scale 3D Scan Datasets


Patric Schmitz, Timothy Blut, Christian Mattes, Leif Kobbelt
IEEE Computer Graphics and Applications
pubimg

Digitalization of 3D objects and scenes using modern depth sensors and high-resolution RGB cameras enables the preservation of human cultural artifacts at an unprecedented level of detail. Interactive visualization of these large datasets, however, is challenging without degradation in visual fidelity. A common solution is to fit the dataset into available video memory by downsampling and compression. The achievable reproduction accuracy is thereby limited for interactive scenarios, such as immersive exploration in Virtual Reality (VR). This degradation in visual realism ultimately hinders the effective communication of human cultural knowledge. This article presents a method to render 3D scan datasets with minimal loss of visual fidelity. A point-based rendering approach visualizes scan data as a dense splat cloud. For improved surface approximation of thin and sparsely sampled objects, we propose oriented 3D ellipsoids as rendering primitives. To render massive texture datasets, we present a virtual texturing system that dynamically loads required image data. It is paired with a single-pass page prediction method that minimizes visible texturing artifacts. Our system renders a challenging dataset in the order of 70 million points and a texture size of 1.2 terabytes consistently at 90 frames per second in stereoscopic VR.

» Show Videos



A Three-Level Approach to Texture Mapping and Synthesis on 3D Surfaces


Kersten Schuster, Philip Trettner, Patric Schmitz, Leif Kobbelt
Proceedings of the ACM on Computer Graphics and Interactive Techniques, Vol. 3, No. 1, 2020
pubimg

We present a method for example-based texturing of triangular 3D meshes. Our algorithm maps a small 2D texture sample onto objects of arbitrary size in a seamless fashion, with no visible repetitions and low overall distortion. It requires minimal user interaction and can be applied to complex, multi-layered input materials that are not required to be tileable. Our framework integrates a patch-based approach with per-pixel compositing. To minimize visual artifacts, we run a three-level optimization that starts with a rigid alignment of texture patches (macro scale), then continues with non-rigid adjustments (meso scale) and finally performs pixel-level texture blending (micro scale). We demonstrate that the relevance of the three levels depends on the texture content and type (stochastic, structured, or anisotropic textures).

» Show BibTeX

@article{schuster2020,
author = {Schuster, Kersten and Trettner, Philip and Schmitz, Patric and Kobbelt, Leif},
title = {A Three-Level Approach to Texture Mapping and Synthesis on 3D Surfaces},
year = {2020},
issue_date = {Apr 2020},
publisher = {The Association for Computers in Mathematics and Science Teaching},
address = {USA},
volume = {3},
number = {1},
url = {https://doi.org/10.1145/3384542},
doi = {10.1145/3384542},
journal = {Proc. ACM Comput. Graph. Interact. Tech.},
month = apr,
articleno = {1},
numpages = {19},
keywords = {material blending, surface texture synthesis, texture mapping}
}





Calibratio - A Small, Low-Cost, Fully Automated Motion-to-Photon Measurement Device


Sebastian Pape, Marcel Krüger, Jan Müller, Torsten Wolfgang Kuhlen
10th Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS), 2020
pubimg

Since the beginning of the design and implementation of virtual environments, these systems have been built to give the users the best possible experience. One detrimental factor for the user experience was shown to be a high end-to-end latency, here measured as motionto-photon latency, of the system. Thus, a lot of research in the past was focused on the measurement and minimization of this latency in virtual environments. Most existing measurement-techniques require either expensive measurement hardware like an oscilloscope, mechanical components like a pendulum or depend on manual evaluation of samples. This paper proposes a concept of an easy to build, low-cost device consisting of a microcontroller, servo motor and a photo diode to measure the motion-to-photon latency in virtual reality environments fully automatically. It is placed or attached to the system, calibrates itself and is controlled/monitored via a web interface. While the general concept is applicable to a variety of VR technologies, this paper focuses on the context of CAVE-like systems.

» Show Videos
» Show BibTeX

@InProceedings{Pape2020a,
author = {Sebastian Pape and Marcel Kr\"{u}ger and Jan M\"{u}ller and Torsten W. Kuhlen},
title = {{Calibratio - A Small, Low-Cost, Fully Automated Motion-to-Photon Measurement Device}},
booktitle = {10th Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS)},
year = {2020},
month={March}
}





Towards a Graphical User Interface for Exploring and Fine-Tuning Crowd Simulations


Andrea Bönsch, Marcel Jonda, Jonathan Ehret, Torsten Wolfgang Kuhlen
IEEE Virtual Humans and Crowds for Immersive Environments (VHCIE), 2020
pubimg

Simulating a realistic navigation of virtual pedestrians through virtual environments is a recurring subject of investigations. The various mathematical approaches used to compute the pedestrians’ paths result, i.a., in different computation-times and varying path characteristics. Customizable parameters, e.g., maximal walking speed or minimal interpersonal distance, add another level of complexity. Thus, choosing the best-fitting approach for a given environment and use-case is non-trivial, especially for novice users.

To facilitate the informed choice of a specific algorithm with a certain parameter set, crowd simulation frameworks such as Menge provide an extendable collection of approaches with a unified interface for usage. However, they often miss an elaborated visualization with high informative value accompanied by visual analysis methods to explore the complete simulation data in more detail – which is yet required for an informed choice. Benchmarking suites such as SteerBench are a helpful approach as they objectively analyze crowd simulations, however they are too tailored to specific behavior details. To this end, we propose a preliminary design of an advanced graphical user interface providing a 2D and 3D visualization of the crowd simulation data as well as features for time navigation and an overall data exploration.

» Show Videos
» Show BibTeX

@InProceedings{Boensch2020b,
author = {Andrea B\"{o}nsch and Marcel Jonda and Jonathan Ehret and Torsten W. Kuhlen},
title = {{Towards a Graphical User Interface for Exploring and Fine-Tuning Crowd Simulations}},
booktitle = {IEEE Virtual Humans and Crowds for Immersive Environments (VHCIE)},
year = {2020},
month={March}
}





Joint Dual-Tasking in VR: Outlining the Behavioral Design of Interactive Human Companions Who Walk and Talk with a User


Andrea Bönsch, Torsten Wolfgang Kuhlen
IEEE Virtual Humans and Crowds for Immersive Environments (VHCIE), 2020
pubimg

To resemble realistic and lively places, virtual environments are increasingly often enriched by virtual populations consisting of computer-controlled, human-like virtual agents. While the applications often provide limited user-agent interaction based on, e.g., collision avoidance or mutual gaze, complex user-agent dynamics such as joint locomotion combined with a secondary task, e.g., conversing, are rarely considered yet. These dual-tasking situations, however, are beneficial for various use-cases: guided tours and social simulations will become more realistic and engaging if a user is able to traverse a scene as a member of a social group, while platforms to study crowd and walking behavior will become more powerful and informative. To this end, this presentation deals with different areas of interaction dynamics, which need to be combined for modeling dual-tasking with virtual agents. Areas covered are kinematic parameters for the navigation behavior, group shapes in static and mobile situations as well as verbal and non-verbal behavior for conversations.

» Show Videos
» Show BibTeX

@InProceedings{Boensch2020a,
author = {Andrea B\"{o}nsch and Torsten W. Kuhlen},
title = {{Joint Dual-Tasking in VR: Outlining the Behavioral Design of Interactive Human Companions Who Walk and Talk with a User}},
booktitle = {IEEE Virtual Humans and Crowds for Immersive Environments (VHCIE)},
year = {2020},
month={March}
}






Previous Year (2019)
Disclaimer Home Visual Computing institute RWTH Aachen University