News

Jun 17, 2017: Haptic and hand tracking demos at the Open Campus 2017.

Feb-Apr 2017: David Vilela (Mechanical Engineering Laboratory, University of Coruna, Spain) visited our lab. He is working on benchmarks to compare different intersection calculation methods in collisions, and also different force models.

Feb 2017: G. Zachmann and J. Teuber visited the Mahidol University in Bangkok, Thailand as part of a delegation from the University of Bremen. The goal of the visit was to foster the cooperation between the two universities and lay ground-work for future colaborations.

Jun 2016: Radio Bremen visited our lab to film the works of the Creative Unit "Intra-Operative Information" for a news magazine on the local TV station. Click here for the film at Radio Bremen. And Click here for the same film on our Website.

May 16, 2016: Patrick Lange was honored with the SIGSIM Best PhD Award at the ACM SIGSIM PADS Conference 2016.

Jun 19-21, 2015: G. Zachmann gives invited talk at the DAAD-Stipendiatentreffen in Bremen, Germany.

Jun 2015: Haptic and hand tracking demos at the Open Campus 2015.

Dec 08-10, 2014: ICAT-EGVE 2014 and EuroVR 2014 conferences at the University of Bremen organized by G. Zachmann.

Sep 25-26, 2014: GI VR/AR 2014 conference at the University of Bremen organized by G. Zachmann.

Sep 24-25, 2014: VRIPHYS 2014 conference at the University of Bremen organized by G. Zachmann .

Feb 4, 2014: G. Zachmann gives invited talk on Interaction Metaphors for Collaborative 3D Environments at Learntec.

Jan 2014: G. Zachmann got invited to be a Member of the Review Panel in the Human Brain Project for the Competitive Call for additional project partners

Nov 2013: Invited Talk at the "Cheffrühstück 2013"

Oct 2013: Dissertation of Rene Weller published in the Springer Series on Touch and Haptic Systems.

Jun 2013: G. Zachmann participated in the Dagstuhl Seminar Virtual Realities (13241)

Jun 2013: Haptic and hand tracking demos at the Open Campus 2013.

Jun 2013: Invited talk at Symposium für Virtualität und Interaktion 2013 in Heidelberg by Rene Weller.

Apr 2013: Rene Weller was honored with the EuroHaptics Ph.D Award at the IEEE World Haptics Conference 2013.

Jan 2013: Talk at the graduation ceremony of the University of Bremen by Rene Weller.

Oct 2012: Invited Talk by G. Zachmann at the DLR VROOS Workshop Servicing im Weltraum -- Interaktive VR-Technologien zum On-Orbit Servicing in Oberpfaffenhofen, Munich, Germany.

Oct 2012: Daniel Mohr earned his doctorate in the field of vision-based pose estimation.

Sept 2012: G. Zachmann: Keynote Talk at ICEC 2012, 11th International Conference on Entertainment Computing.

Sep 2012: "Best Paper Award" at GI VR/AR Workshop in Düsseldorf.

Sep 2012: Rene Weller earned his doctorate in the field of collision detection.

Aug 2012: GI-VRAR-Calendar 2013 is available!

A Benchmarking Suite for Static Collision Detection Algorithms

There are a number of algorithms for collision detection between rigid objects. Unfortunately, it is extremely difficult to evaluate and compare collision detection algorithms, because in general they are very sensitive to specific scenarios. We propose a benchmarking suite which can evaluate both the performance as well as the quality of the collision response. The former is achieved by densely sampling the configuration space of a large number of highly detailed objects; the latter is achieved by a novel methodology that comprises a number of models for certain collision scenarios. With these models, we compare the force and torque signals both in direction and magnitude. It has been kept very simple so that other researchers can easily reproduce the results and compare their algorithms.

Performance Benchmark

Almost all collision detection libraries for static collision detection between rigid objects are based on bounding volume hierarchies (BVHs). If the bounding volume (BV) of an object does not intersect a volume higher in the tree, then it cannot intersect any object below that node. So, they are all rejected very quickly. If two objects overlap, the recursive traversal during the collision check should quickly converge towards the colliding polygon pair. So, it is most time consuming if the BVHs overlap, but the objects do not. Summarizing, the testing time of pairwise collision detection algorithms depends mainly on the configuration of the two objects and their shapes, i.e. the positions, orientations, and the distance.

Therefore, it seems to be reasonable for a well-balanced benchmarking procedure to test as many configurations for a given distance as possible. Based on this observation, our benchmarking suite automatically generates a large set of configurations for a user defined pair of objects and a list of distances.

picture

The picture above shows a set of configurations that our benchmarking suite has generated. Every red dot marks the closest point of the moving object to the fixed object for one special transformation and distance. Click on the picture to see a short video of the configuration generation. For further details about the configuration generation algorithms we used in our benchmarking suite, we refer the interested user to our WSCG-Paper.

Quality Benchmark

Especially with forces, human perception is very sensitive to unexpected discontinuities both in magnitude and direction. Consequently, collision detection algorithms should provide stable and continuous forces and torques, even in extreme situations like high impact velocities or large contact areas. Moreover, they should provide these forces at interactive rates.

In order to determine the collision response quality of an algorithm, we pursue a different approach, because computing realistic forces and torques from detailed objects in complex contact scenarios is highly non-trivial. Because of that, we propose to use fairly simple scenarios and geometry tests to measure the quality of the collision response. We believe that this approach is even more warranted because different collision handling systems use different measures for the force and torque computations. For instance, penalty-based methods usually use a translational penetration depth or the penetration volume, impulse based collision response schemes often need the first time of impact.

picture

Another advantage of simple scenarios is that we can model them, which allows us to calculate the theoretically expected forces and torques analytically for different collision response schemes. The comparison of this analytically derived ground truth data with the data gathered from the benchmarked algorithms allows us to define several measures, such as deviations and discontinuities of forces and torques, or the measurement of noise. For further details about the Quality Benchmark we used in our benchmarking suite, we refer the interested user to our VRST2010-Paper.

Publications

Features


Prerequisites


Sample Plots



Examples of automatically generated diagrams. Click here to see all results.

Download

Here, you can download the source code of our benchmarking suite for free. It is licensed under the GPL.

Supported Collision Detection Libraries so far

FreeSOLID
OPCODE
V-Collide
PQP
Dop-Tree and BoxTree

If you use our benchmarking suite for testing your own collision detection library, it would be quite nice, if you could send us your wrapper code, so that we can integrate it to our download for other researchers.

Set of Objects and Configurations

Together with our benchmarking suite, we offer a set of objects and a set of precomputed configurations for these objects. Each object is available in several resolutions. We recommend to use the precomputed configurations for your benchmarks because configuration generation is very time consuming (e.g. 2 weeks of computation on 8 3GHz-Pentium 4`s for the Eagle (low sampled version)).

Configurations were generated using


Most of the objects are free for non commercial use. For some models, the owners have defined specific licenses.

Apollo Capsule 1


6 LODs
8-170k polygons
picture Download object (zip, 11MB) Download configurations (zip, 117MB)

ATST-Walker 1


6 LODs
4-152k polygons
picture Download object (zip, 6MB) Download configurations (zip, 117MB)

Castle 1


6 LODs
14-127k polygons
picture Download object (zip, 4MB) Download configurations (zip, 115MB)

Chair 1


5 LODs
22-114k polygons
picture Download object (zip, 4MB) Download configurations (zip, 100MB)

Cobra 1


6 LODs
2-256k polygons
picture Download object (zip, 14MB) Download configurations (zip, 110MB)

DS9-Space-Station 4


5 LODs
97-584k polygons
picture Download object (zip, 4MB) Download configurations (zip, 98MB)

Eagle 1


5 LODs
98-594k polygons
picture Download object (zip, 26MB) Download configurations (zip, 90MB)

Ferrari 1


5 LODs
61-249k polygons
picture Download object (zip, 11MB) Download configurations (zip, 94MB)

Grid


5 LODs
5-414k polygons
picture Download object (zip, 4MB) Download configurations (zip, 78MB)

Happy Buddha 3


8 LODs
10-1087k polygons
picture Download object (zip, 23MB) Download configurations (zip, 140MB)

Helicopter 1


5 LODs
23-119k polygons
picture Download object (zip, 4MB) Download configurations (zip, 98MB)

Laurel 1


6 LODs
13-271k polygons
picture Download object (zip, 10MB) Download configurations (zip, 115MB)

Lustre 1


6 LODs
6-120k polygons
picture Download object (zip, 4MB) Download configurations (zip, 120MB)

Pipes


5 LODs
10-125k polygons
picture Download object (zip, 3MB) Download configurations (zip, 100MB)

Lock


15 LODs
1-207k polygons
picture Download object (zip, 15MB) Download configurations (zip, 221MB)

Sponge


5 LODs
12-820k polygons
picture Download object (zip, 11MB) Download configurations (zip, 80MB)

Sphere


5 LODs
-k polygons
picture OpenSG built-in Download configurations (zip, 40MB)

Torus


5 LODs
-k polygons
picture OpenSG built-in Download configurations (zip, 90MB)

Hand 2


6 LODs
63-650k polygons
picture Download object (zip, 26MB) Download configurations (zip, 120MB)

Dragon 3


5 LODs
174-871k polygons
picture Download object (zip, 24MB)

Chinese Dragon 5


5 LODs
262-1311k polygons
picture Download object (zip, 41MB)

Circular Box 5


5 LODs
280-1402k polygons
picture Download object (zip, 44MB)

Elephant 5


5 LODs
614-3074k polygons
picture Download object (zip, 88MB)

Female Pelvis 6


5 LODs
200-1000k polygons
picture Download object (zip, 33MB)

Filigree 7


5 LODs
205-1028k polygons
picture Download object (zip, 23MB)

Gargoyle 6


5 LODs
345-1726k polygons
picture Download object (zip, 44MB)

Knot 5


5 LODs
191-957k polygons
picture Download object (zip, 41MB)

Raptor 7


5 LODs
400-2000k polygons
picture Download object (zip, 50MB)

Armchair 6


5 LODs
142-712k polygons
picture Download object (zip, 20MB)

Vase 5


5 LODs
358-1792k polygons
picture Download object (zip, 40MB)

Object Resources

1. CTU

2. The Stanford 3D Scanning Repository

3. Large Geometric Models Archive

4. Joerg Gerlach

5.Model is provided courtesy of INRIA by the AIM@SHAPE Shape Repository

6.Model is provided courtesy of VCG-ISTI by the AIM@SHAPE Shape Repository

7.Model is provided courtesy of SensAble technologies by the AIM@SHAPE Shape Repository