80 lines
2.1 KiB
Python
80 lines
2.1 KiB
Python
#!/usr/bin/python3
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"""
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SPVO = Sparse Voxel Octree
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A Sparse Voxel Octree is a way of storing multidimensional data. (In this case it is 3D Data.)
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It works similarly to a Sparse Voxel Matrix, but it is a bit compressed.
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In a Sparse Voxel Octree, you have a root-node. The root node gets split up into 8 child nodes,
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which can be all split up into 8 more child nodes which can be split up too and so on.
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Thanks to this "compression", there are no zero values on places where there is just air unlike as in a normal matrix.
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"""
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class Node:
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def __init__(self):
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self.children = [None] * 8
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self.leaf = True
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class SparseVoxelOctree:
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def __init__(self, data=None):
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self.root_node = Node()
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self.origin = (0, 0, 0)
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self.data = data
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def _get_child_index(self, x, y, z, size):
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index = 0
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if x >= size // 2:
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index |= 1
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x -= size // 2
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if y >= size // 2:
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index |= 2
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y -= size // 2
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if z >= size // 2:
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index |= 4
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z -= size // 2
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return index, x, y, z
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def _extend_tree(self, x, y, z):
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new_root = Node()
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new_root.leaf = False
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index, nx, ny, nz = self._get_child_index(x, y, z, 2)
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new_root.children[index] = self.root_node
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self.root_node = new_root
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self.origin = (
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self.origin[0] - (x >= 0) * 2 + 1,
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self.origin[1] - (y >= 0) * 2 + 1,
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self.origin[2] - (z >= 0) * 2 + 1
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)
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def _insert(self, node, x, y, z, size):
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while not size == 1:
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index, x, y, z = self._get_child_index(x, y, z, size)
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if node.children[index] is None:
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node.children[index] = Node()
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size //= 2
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node.leaf = True
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def insert(self, x, y, z):
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# move origin if necessary
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while not (0 <= x < 2 ** 30 and 0 <= y < 2 ** 30 and 0 <= z < 2 ** 30):
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self._extend_tree(x, y, z)
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x, y, z = (
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x - self.origin[0],
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y - self.origin[1],
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z - self.origin[2]
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)
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self._insert(self.root_node, x, y, z, 2 ** 30)
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