Labeling Streets Along a Route in Interactive 3D Maps Using Billboards
Labeling Streets Along a Route in Interactive 3D Maps Using Billboards
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DOI：
10.1007/978-3-319-16787-9_16
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
N. Schwartges;Benjamin Morgan;J. Haunert;A. Wolff
中科院分区：
文献类型：
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作者：
N. Schwartges;Benjamin Morgan;J. Haunert;A. Wolff
我们考虑了标记线性对象的问题，例如街道、非交互式3D地图，其中用户可以连续平移、缩放和旋转场景的透视图。我们动态地注释属于用户路线的街道，假设地图当前可见部分内的路线的未来路线是已知的或被很好地预测的。我们使用广告牌作为注释，即每个标签都是一个包含注释文本的矩形，面向用户，放置在要标记的街道中点上方一定距离处，并通过垂直线段(引线)连接到该点。我们的目标是保持一个无重叠的标签，以实时响应视图的变化。为此，我们动态地改变领导人的长度。为了实现标签的顺畅移动，我们不严格禁止标签-标签重叠。我们提出了一种力制导算法，将力应用于标签，使重叠的标签相互排斥，同时使引线尽可能接近其所需的长度。在真实世界的数据上，使用真实数量的标签，我们获得了每秒400帧以上的帧速率，同时与具有固定前导长度的算法相比，大大减少了每帧的总重叠区域。
We consider the problem of labeling linear objects, such as streets, ininteractive 3D maps, where the user can continuously pan, zoom, and rotate a perspective view of the scene. We dynamically annotate streets that belong to a user’s route, assuming that the future course of the route, within the currently visible part of the map, is known or well predicted. We usebillboardsas annotations, that is, each label is a rectangle holding the annotation text, is oriented towards the user, placed at some distance above the midpoint of the street to be labeled, and connected to the point by a vertical line segment, theleader. Our goal is to maintain an overlap-free labeling that reacts to changes of the view in real time. To this end, we dynamically vary the lengths of the leaders. In order to achieve that labels move smoothly, we do not strictly forbid label–label overlaps. We present a force-directed algorithm that applies forces to labels to cause overlapping labels to repel each other, while keeping leaders as close to their desired length as possible. On real-world data, with a realistic number of labels, we obtain frame rates of more than 400 frames per second, while drastically reducing the total overlapped area per frame, compared to an algorithm with fixed leader lengths.