1. 1 Haptic Systems 530-655 Mohsen Mahvash Lecture 7 18/1/06

2. 2  A review of last lecture  Change of force at the edges  Force shading  Friction rendering  References Haptic rendering of contact

3. 3

4. 4 Change of force direction During sliding contact, at the moment that the god-object is crossing an edge, the direction of force is changed.

5. 5 Change of force amplitude During sliding contact, at the moment that the god-object is crossing an edge, the amplitude of force is changed.

6. 6 Vertex normal

7. 7 Vertex local surface A local coordinate can be defined at each vertex of the object surface

8. Area interpolation

9. 9 local coordinates at contact points The direction of normal vector at point of contact is continuously changed Local surfaces at different contact points

10. 10 Proxy location Local surface Object surface proxy tip project tip sub-goal: the closest point of the local surface to the the tip proxy: the closest point of the object active surface to the sub- goal proxy

11. 11 Friction rendering Local surface Object surface proxy sub-goal tip sub-goal: the closest point of the local surface to the the tip proxy: the closest point of the object active surface to the sub- goal proxy sub-goal tip

12. 12 Friction rendering Local surface Object surface proxy tip sub-goal: the closest point of the local surface to the the tip proxy: the closest point of the object active surface to the sub- goal tip projection sub-goal

13. 13 Tomorrow Haptic assistance: Applications and Design Considerations (guest lecturer Panadda Marayong) References: 1.C.B. Zilles, J.K. Salisbury, A constraint-based god-object method for haptic display International Conference on Intelligent Robots and Systems-Volume 3. 1995. 2.D. C. Ruspini, K Kolarov, O Khatib - The haptic display of complex graphical environments, SIGGRAPH, 1997. 3. Mahvash, M., Hayward, V. 2004. High Fidelity Haptic Synthesis of Contact With Deformable Bodies. IEEE Computer Graphics and Applications. 24(2): 48-55, 2004. 4.V Hayward, B Armstrong, A New Computational Model of Friction Applied to Haptic Rendering, Lecture Notes in Control and Information Sciences, Vol. 250, Springer- Verlag, pp. 403-412.