Abstract:
The three-dimensional modeling techniques based on construction drawings have illustrated a good prospect of applications in virtual simulation, scene design, engineering modeling and calculation. Due to the complexity and diversity of structure information in construction drawings, the three-dimensional reconstruction based on construction drawings is still a great challenge. In this paper, a modeling method based on semantic mapping was presented to reconstruct three-dimensional models of solar-greenhouses from construction drawings. The construction drawings of solar-greenhouse with DXF formats were analyzed to obtain the structure elements which consisted of basic graphics primitives, text and annotation etc. The semantics models of the main characteristic components of solar-greenhouse were then built, and used to classify these structure elements into individual semantic components according to the recognition and understanding of their coordination, geometric features and text information. Moreover, the parameters models were also defined based on the hierarchical control parameters which consisted of all the structure, topology and texture parameters of the three-dimensional solar-greenhouses. After the semantic mapping mechanism between semantics and parameters models was built, the semantic driving method could conveniently generate the three-dimensional models from construction drawings. Among the above steps, the object-oriented analysis and design were used to refine two-dimensional geometric primitives and three-dimensional objects, and the photo-realistic rendering techniques were used to implement the visualization of the generated models. Based on the semantics-driven and parameters-driven mechanism, the presented method integrated CAD drawings, three-dimensional modeling and visualization techniques to reconstruct the three-dimensional solar-greenhouses from construction drawings. Finally, two sets of construction drawings were respectively tested. The results demonstrate this method is not only beneficial to improve the efficiency in reading the drawings, but the generated model with fidelity, interactivity and photo-realistic features can be used for the construction quantity and cost computation, structural optimization and the virtual exhibition.