1. Bubble Simulation for the Hysteroscopy Simulator
Michel Estermann
Eveline Mattle
Februar 2006

2. VR in Medicine Homework
Contents
Hysteroscopy Simulator
Bubbles
Forces acting on a bubble
Velocity of a bubble
Results
Discussion and Conclusions
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3. Hysteroscopy Simulator
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4. Hysteroscopy Simulator
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Bubble
Model:
Sphere with radius r
Generation:
Bubblepool
Randomly generated size
During cutting
Display:
Billboarding
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6. Forces acting on a Bubble
Buoyancy
Gravity
Forces between two bubbles
Repelling force
Viscous force
Forces between bubbles and objects
Influence of the Fluid velocity on a bubble
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Velocity of a bubble
Because it is assumed, that the bubbles have no mass the sum of all the forces has to be zero.
Some of the forces are dependent of the velocity of the bubbles, so a equation for the velocity can be found.
With the velocity the position of the bubbles can be calculated discretely.
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Results
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Results
Several assumptions and approximations used in this work leads to certain limitations:
Large velocity changes between update-steps possible
Considering time for independence of computation time
No deformation of bubbles
No fusion of bubbles
Difficulties to find the right parameters
Current implementation: no interaction with the objects
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10. Discussion and Conclusions
Because the bubbles interact now with themselves and with the fluid around them the simulation looks more realistic.
Because of the Buoyancy an important information about the orientation is given.
Next step: implement the interaction of the bubbles with the objects.
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References
[1] (2005) –hysteroscopy simulator website. Available:
[2] S.T. Greenwood and D. H. House, “Better with bubbles: Enhancing the visual realism of simulated fluid”, in SCA ’04: Proc. Of the 2004 ACM SIGGRAPH/Eurographics symposium on Computer animation. New York, NY, USA: ACM Press, 2004, pp [online]. Available:
[3] H. Kueck, C. Vogelsang, and G. Greiner, “Simulation and rendering of liquid foams”, Proc. Graphics Interface ’02, pp.81-88, [Online]. Available:
[4] D. J. Durian, “Foam mechanics at the bubble scale”, Physical Review Letters, vol 75, no. 26, pp , [Online]. Available:
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12. Thanks for your attention!