Terrain Synthesis Based On Feature Lines

Terrain is widely used in landscape design,flight simulation,battlefield environment simulation,film and television animation special effects and games.The terrain of different application scenarios is quite different,so it is necessary to edit the virtual terrain appropriately.The large curve of terrain,such as ridge lines and valley lines,contains many key terrain feature information.It is an effective method in terrain editing to extract and use these feature lines for terrain synthesis.This paper firstly extracts feature lines of large terrain curves,then achieves terrain synthesis based on feature lines,and finally carries out visualization demonstration under Unreal Engine 4 environment.The main research work is as follows:(1)Extraction of feature lines(ridge and valley)of topographic curveFirstly,according to the characteristics of large terrain feature curve,the extraction of terrain feature lines is designed and realized.Through detection,all candidate points of ridges are found and connected,and the closed polygon is fractured.For better visual effects,all shorter branches are eliminated,resulting in a clearly visible terrain feature lines.On the basis of PPA algorithm,some improvements were made to repair the fault,making the extraction results more continuous.(2)Terrain synthesis based on feature linesBy using the real terrain sample map and the sketch provided by the user,different feature points are obtained through the detection and screening of the extraction results of feature lines.Based on this,the candidate faces are matched and placed,and the feature areas and non-feature areas are matched and placed respectively.Finally,the synthetic terrain with realistic terrain features that conforms to the constraints of user sketch features can be obtained.