Future Work

Additional Feedback

The force feedback was difficult to feel during testing. The vibration caused by the drill made feeling some forces impossible. Many errors were caused when the feedback could not be felt. Adding sound to the program could increase the experience. Sound could give the user additional feedback. For example, the closer the distance between two objects the higher the frequency.

Density

A density property exists in the octree structure but is currently unused. This is when collisions occur with a leaf node and should be viewed as object persistence. Currently, leaf nodes are removed after a collision between a leaf node and the cursor object occurs. The possible extension is to modify a counter when collisions occur and only remove the leaf when the counter expires. This can be extended to represent 3D data with density information.

Graphics improvements

The current program displays the maximum haptics workspace as the screen dimensions. This should be changed to better fit the drilling area. A zoom feature is not implemented and the current camera angle rotations are controlled by the keyboard. Ideally the haptic device should control this. The haptics could be used to position the viewing angle by capturing the motion of the haptics endpoint. Rotations could also be obtained from the orientation of the haptic device.

The marching cubes algorithm needs to be adjusted. Holes appear in the current implementation. The problem is when one branch has all 8 leaf nodes removed.

Alternative Device

Stronger force feedback should be tested to prevent removing desired material. Currently the forces provide the user with the knowledge that the desired shape is near but the user can easily overpower the force feedback. Larger haptic devices from SensAble Technologies provide increased forces.

The program should be easily scalable to work with a larger device by SensAble. The other devices are capable of rendering stronger forces and have greater accuracy. The levels of force would have to be adjusted in an extended program but most other features are similar between all SensAble devices because they all can use the OpenHaptics Toolkit and the HDAPI.

Voxelization

It is possible to precompute the collision space of for the STL object. The octree object would be modified to store the shape of the STL object. This could remove using the SWIFT collision detection package with the tradeoff being that the resolution of the octree would determine the accuracy of the final shape.

August Test 1: Torus

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