Tetra-trees properties in graphic interaction

The localization of the components of an object near to a device before obtaining the real interaction is usually determined by means of a proximity measurement to the device of the object’s features. In order to do this efficiently, hierarchical decompositions are used, so that the features of the objects are classified into several types of cells, usually rectangular.In this paper we propose a solution based on the classification of a set of points situated on the device in a little-known spatial decomposition named tetra-tree. Using this type of spatial decomposition gives us several quantitative and qualitative properties that allow us a more realistic and intuitive visual interaction, as well as the possibility of selecting inaccessible components. These features could be used in virtual sculpting or accessibility tasks.In order to show these properties we have compared an interaction system based on tetra-trees to one based on octrees.

► Analysis of quantitative and qualitative properties of tetra-tree regarding octree.
► Spatial decomposition for localization which improves construction and interaction.
► Improving of quality, visual feed-back and precision, applicable to haptics.
► Selection of inaccessible components without accessory intersection algorithms.
► An interaction system with smooth transition between frames including large models.