Automatic Techniques for Texture Mapping in Virtual Urban Environments

Many methods exist for automatically generating three dimensional models of urban environments at various levels of detail. To improve the realism of these models texture maps are applied to the building facades. This paper focuses on techniques which progress towards the automatic application of textural detail to building facades. In particular attention is paid to residential scenes where buildings are occluded by many objects such as vegetation and fences. The approach undertaken uses a set of images for each building being textured. From this set a single building image is created by identifying the building and removing occluding objects using a depth map. Further processing of the building image is undertaken to generate two texture maps, the wall map and the object map. The wall map contains a repeatable wall pattern extracted automatically from the building facade. The object map contains the spatial arrangement of features on a transparent background. The features are objects on the building facade such as windows and doors. These two texture maps are combined on the graphics card to permit the final textural detail of the building to be visualised