基于视点的3维模型动态注记方法

3维文字注记对于直观表达3维场景中对象的文本信息非常重要，但现有研究大多忽略这一问题，该文主要针对城市环境3维建筑物模型的注记问题，提出一种基于视点位置和方向的动态注记方法。该方法依据3维模型离视点的远近对文字注记位置进行分层处理。在视点远近变换时，选取建筑对象的不同细节层次模型作为文字注记的计算对象。进而依据视点的方向实时计算文字注记的方向，达到动态的注记效果。这种动态的注记方法可以避免因视点变换而产生的注记与3维模型之间的遮挡关系，也可以避免场景因注记过多而产生的杂乱情形。实验表明，该方法具有较好的可视化效果。

One Dynamic Text Mark Method for 3D Models Based on Viewpoint

Text Mark is very important for intuitively expressing the information of 3D objects in 3D City Model, however, few research works pay attention on it. In order to resolve the problem on 3D text mark in 3D City Model, we present one dynamic text mark method based on the position and orientation of the viewpoint. This method process text mark in different levels depends on 3D object＇s distances from the viewpoint. When the viewpoint changing, the different LOD levels of the objects＇ models are selected for the calculation of text mark position, and the direction of the viewpoint is used to calculate directons of text marks. This dynamic text mark method can avoid text occluding by 3D models when viewpoint is changing and also can avoid disorderly mark effect to the scene by add many text. The experiment shows that this method has a good visual effect.