4.2 Dynamic Continuous Triangle Network
The network in the world space is determined by a world space location W (V) to each binary tree. When any two triangles do not coincide on the common point or the public side, the triangular binary tree forms a continuous grid, which is called a binary tree triangular network.
Figure 4 shows a triangular T of a typical adjacent relationship in the binary tree triangular net, we call TB as a base of shared base edges (V0, V1), referring to the left neighbors of the left (Va, V0), TR is called a shared right neighbor on the right (V1, VA).
An important nature of the binary tree triangular network is: neighbors may come from both the same two fork T, or a fine L 1 layer of left neighbor or right neighbors, or L-1 layer than t Base neighbor.
When T and TB belong to the same layer L, we refer to (T, TB) as a block, Figure 4 shows the split and merge process of the triangular network containing blocks. After segmentation, the child (T0, T1) instead of T, and (TB0, TB1) replaced TB. The segmentation operation creates a new node VC at the center of the block. If the triangular T does not have a base neighbor TB, only T is divided. When T and TB (if there is a TB), the square (T, TB) can be merged when both the children in the same triangle. We call such a situation as a merged block in a triangular network.
A triangular network may be determined by a triangular network after a series of split and merge operations.
The split and merge operations are typically activated using a vertex in which simple temporary adjacent forms is provided. At interval
At the time, consider the segmentation of (t, tb) in Figure 4. We can move the VC directly to the new location WC = W (VC), but in accordance with the time from the unsearched base edge, WM = (W (V0) W (V1)) / 2 linear movement The mobile function is Wa (T) = (1-T) WM TWC. Merger can also be activated in the same way.
When the triangular neighbor TB comes from a more rough hierarchy, it cannot be divided directly. In order to make T mandatory segmentation, the TB must first be mandatory, it can be seen so that this will cause a deeper recursive segmentation. Figure 5 shows a case of 4 segmentation.
A basic grid greater than a triangle can be used to represent any type of surface with a boundary.
