Пример #1
0
/* get cost of sah(surface area heuristic) method for certain plane */
double get_sah_cost(double plane, aabb &voxel, int num_left, int num_right) 
{
	aabb voxel_left, voxel_right;
	voxel.split_aabb(dim, plane, voxel_left, voxel_right);
	double sa_left = voxel_left.get_surface_area();
	double sa_right = voxel_right.get_surface_area();
	double sa_union = voxel.get_surface_area();

	return get_cost(sa_left / sa_union, sa_right / sa_union, num_left, num_right);
}
Пример #2
0
/* build kd-tree */
kdtree::kdtree(aabb &voxel, vector<primitive*> &pris, int depth, kdtree* parent)
{
	parent_kdtree = parent;
	left_kdtree = right_kdtree = NULL;
	bbox = voxel;

	/* end criteria; make this leaf */
	if (depth > maximum_depth || pris.size() < 1)
	{
		primitives = pris;
	}

	/* general case: determine whether and how to devide current voxel */
	else
	{
		double cost_asleaf = cost_i * pris.size();	
		cost_min = 1E100;							

		for (dim = 0; dim < 3; dim++)
		{
			get_best_plane(pris, voxel);
		}

		/* internal node; divide further */
		if (cost_min < cost_asleaf)
		{
			vector<primitive*> left_pris, right_pris;
			classify_primitives(pris, best_plane, left_pris, right_pris);

			aabb left_voxel, right_voxel;
			voxel.split_aabb(best_dim, best_plane, left_voxel, right_voxel);

			left_kdtree = new kdtree(left_voxel, left_pris, depth + 1, this);
			right_kdtree = new kdtree(right_voxel, right_pris, depth + 1, this);
		}

		/* leaf; division end */
		else							
		{
			primitives = pris;
		}
	}
}