This work develops a system of spherical magnetic tangi- bles, GaussMarbles, that exploits the unique affordances of spherical tangibles for interacting with portable physical con- straints. The proposed design of each magnetic sphere in- cludes a magnetic polyhedron in the center. The magnetic polyhedron provides bi-polar magnetic fields, which are ex- panded in equal dihedral angles as robust features for track- ing, allowing an analog Hall-sensor grid to resolve the near- surface 3D position accurately in real-time. Possible inter- actions between the magnetic spheres and portable physical constraints in various levels of embodiment were explored us- ing several example applications.

1. GaussMarbles:SphericalMagneticTangiblesfor
InteractingwithPortablePhysicalConstraints
Han-ChihKuo,Rong-HaoLiang,Long-FeiLin,Bing-YuChen
NationalTaiwanUniversity

5. InteractiveSurface ConstructiveAssembly Token+Constraint
Token+Constraint Systems for Tangible Interaction with Digital Information
(Ullmer et al. TOCHI ‘05)
TangibleUserInterfaces

6. InteractiveSurface ConstructiveAssembly Token+Constraint
MagGetz
(Hwang et al. UIST ’13)
Tangible Magnetic
Appcessories
(Bianchi et al. TEI ’13)
Tangible Remote Controllers
for Wall-size Displays
(Jansen et al. CHI ’12)
TrackingToken+ConstraintInteractionsonPortablePlatforms
Token+StrictConstraint

8. TrackingBall+ConstraintInteractionsonStationaryPlatforms
Ball+LooseConstraint
inFORM
(Follmer et al. UIST ’13)

9. Ball+ConstraintInteractionsonPortablePlatforms

10. TrackingBall+ConstraintInteractionsonStationaryDisplays
camera camera
magnetic-fieldcamera
UIST’11, October 16–19, 2011, Santa Barbara, CA, USA
BetterFormFactors
Vision-basedObjectTrackingTechnologies
GaussSense
(Liang et al. UIST ’12)
Portico
(Avrahami et al. UIST ’11)

11. ChallengesofMagneticTrackingOneofthebipolarmagneticfield
maydisappearwhilerolling

12. Solution:MagneticRegularPolyhedron
Expandingmagneticfieldsinequaldihedralanglestomakethe
bipolarmagneticfieldsvisibleatanydirection

13. Solution:MagneticRegularPolyhedron
Expandingmagneticfieldsinequaldihedralanglestomakethe
bipolarmagneticfieldsvisibleatanydirection

14. ExplorativeStudy
differentsizesdifferentfaces
Formfactorsvs.trackingperformances

15. Formfactorsvs.trackingperformances
ExperimentalApparatus

16. servo motor
stabilizer
analog
Hall-sensor
grid
Formfactorsvs.trackingperformances
ExperimentalApparatus

17. servo motor
stabilizer
analog
Hall-sensor
grid
Formfactorsvs.trackingperformances
ExperimentalApparatus
singlemagnet
16mm-radius
6-face
13.5,16,18.5,21mm-radius
4,6,8,12-face
16mm-radius

18. servo motor
stabilizer
analog
Hall-sensor
grid
Formfactorsvs.trackingperformances
ExperimentalApparatus
8(units)×5(positions)×4(hoverheights)
×10(angles)×100(samples)=
160,000 bitmapsofmagneticfields
singlemagnet
16mm-radius
6-face
13.5,16,18.5,21mm-radius
4,6,8,12-face
16mm-radius

19. Formfactorsvs.trackingperformances
DataProcessing
Bipolar-blobcontours North-blobcontours South-blobcontours
3typesofcontour
8(units)×5(positions)×4(hoverheights)
×10(angles)×100(samples)=
160,000 bitmapsofmagneticfields
(maxIntensityMandblobAreaA)

20. Formfactorsvs.trackingperformances
DataProcessing
Bipolar-blobcontours North-blobcontours
1. Centroidofcontours
2. Centroidofpixels(inallcontours)
3. Centroidofmass(inallcontours)
3typesofcontour x
8(units)×5(positions)×4(hoverheights)
×10(angles)×100(samples)=
160,000 bitmapsofmagneticfields
(maxIntensityMandblobAreaA) 3typesofcentroid
South-blobcontours

21. 9Distributions
ofcentroids
Formfactorsvs.trackingperformances
DataProcessing
Bipolar-blobcontours North-blobcontours
1. Centroidofcontours
2. Centroidofpixels(inallcontours)
3. Centroidofmass(inallcontours)
3typesofcontour
3typesofcentroidx d
8(units)×5(positions)×4(hoverheights)
×10(angles)×100(samples)=
160,000 bitmapsofmagneticfields
(maxIntensityMandblobAreaA)
=
South-blobcontours

22. 9Distributions
ofcentroids
Formfactorsvs.trackingperformances
DataProcessing
Bipolar-blobcontours North-blobcontours
1. Centroidofcontours
2. Centroidofpixels(inallcontours)
3. Centroidofmass(inallcontours)
d
mean(d),std(d):
measured
dispersion
8(units)×5(positions)×4(hoverheights)
×10(angles)×100(samples)=
160,000 bitmapsofmagneticfields
3typesofcontour
3typesofcentroidx
(maxIntensityMandblobAreaA)
=
South-blobcontours

23. 0
1
2
3
4
5
6
1M P4 6M 8M 12M
IN-OC IN-OP IN-OM IS-OC IS-OP IS-OM IB-OC IB-OP IB-OMOc-IN Op-IN Om-IN Oc-IS Op-IS Om-IS Oc-IB Op-IB Om- IB
N/A
N/A
N/A
0
1
2
3
4
5
6
(mm)
distance(d)
1.Bi-polarcentroidofmassisthemoststablefeatureforxy-planetracking.
singlemagnet
16mm-radius
4-face
16mm-radius
6-face
16mm-radius
8-face
16mm-radius
12-face
16mm-radius
SummaryofFindings

24. SummaryofFindings
0
1
2
3
4
5
6
1M P4 6M 8M 12M
IN-OC IN-OP IN-OM IS-OC IS-OP IS-OM IB-OC IB-OP IB-OMOc-IN Op-IN Om-IN Oc-IS Op-IS Om-IS Oc-IB Op-IB Om- IB
N/A
N/A
N/A
0
1
2
3
4
5
6
(mm)
distance(d)
1.Bi-polarcentroidofmassisthemoststablefeatureforxy-planetracking.
singlemagnet
16mm-radius
4-face
16mm-radius
6-face
16mm-radius
8-face
16mm-radius
12-face
16mm-radius
2.Polyhedronssupportz-axis
trackingbyusingtheproductof
south-blobareaandintensity
(AS ×MS),andasingle
magnetdoesnot.
3 mm
6 mm
9 mm
0
50
100
150
200
0
50
100
150
200
0
50
100
150
200
0
50000
100000
150000
0
50000
100000
150000
0
50000
100000
150000
(gauss)
200
150
100
50
0
150000
100000
50000
0
(gaussxmm2)
a b4-face 6-face 8-face 12-face

25. SummaryofFindings
h = 12 mm
h = 9 mm
h = 6 mm
h = 3 mm
m
Om- IB
2
4
0
2
0
2
0
2
0
(mm)
distance(d)
a
3.Morefacesyieldgreater
accuracy,butaccuracydrops
assensingdistanceincreases.
(cont’d)
4face 6face 8face 12face

26. h = 12 mm
h = 9 mm
h = 6 mm
h = 3 mm
m
Om- IB
2
4
0
2
0
2
0
2
0
(mm)
distance(d)
a
3.Morefacesyieldgreater
accuracy,butaccuracydrops
assensingdistanceincreases.
SummaryofFindings
4face 6face 8face 12face4.Smallerpolyhedronsyield
slightlygreateraccuracy.
0
1
2
3
4
5
6
7
8
1 2 3 4
1 2 3 4
h = 3 mm h = 12 mmh = 9 mmh = 6 mm
2
4
0
6
8
(mm)
distance(d)
a b
13.5mm
radius
16mm
radius
19.5mm
radius
21mm
radius
(cont’d)

27. DesigningBall+ConstraintInteractionsonPortablePlatforms
Applications

28. InteractingwithConstraintsonaDisplay
UsingPhysicalConstrainttoManipulateaBall

29. InteractingwithConstraintsonaDisplay
EmbodiedGestures

30. InteractingwithConstraintsonaDisplay
Ball+ConstraintInteractionsonHandheldDisplays

31. InteractingwithConstraintsonaDisplay
conductiverubber
Touchinteractionsonamagneticsphere

32. InteractingwithConstraintsonaDisplay
Clay-madeterritoryasacontinuousconstraint

33. InteractingwithConstraintsonaDisplay
Around-DeviceInteractions

34. InteractingwithaConstraintNearbyaDisplay
UsingPhysicalConstraintstoBridgeDigital-andReal-worldExperiences

35. InteractingwithaConstraintNearbyaDisplay
UsingPhysicalConstraintstoBridgeDigital-andReal-worldExperiences

36. InteractingwithaConstraintDistantfromaDisplay
Velcrostrap
High-frictionMaterialsasPhysicalConstraints

37. InteractingwithaConstraintDistantfromaDisplay
Velcrostrap
High-frictionMaterialsasPhysicalConstraints

38. GaussMarbles:SphericalMagneticTangiblesfor
InteractingwithPortablePhysicalConstraints
Han-ChihKuo,Rong-HaoLiang,Long-FeiLin,Bing-YuChen
NationalTaiwanUniversity
Thanks!Questions?
Theproposedmagneticregularpolyhedron
designenables
• stable3DtrackingbyananalogHall-sensorgrid
withoutprioriknowledge
• theexplorationsofball+constraintinteraction
onportableplatforms
Conclusion