Résumé
Reconstruction of a real tree from scattered scanned points is a new challenge in virtual reality. Although many progresses are made on main branch structures and overall shape of a tree, reconstructions are still not satisfactory in terms of silhouette and details. We do think that 3D reconstruction of the tree crown shapes may help to constrain accurate reconstruction of complete real tree geometry. We propose here a novel approach for tree crown reconstruction based oil ail improvement of alpha shape modeling, where the data are points unevenly distributed in a Volume rather than oil a surface only. The result is ail extracted silhouette mesh model, a concave Closure of the input data. We Suggest an appropriate scope of proper alpha values, so that the reconstruction of the silhouette mesh is a valid manifold Surface. Experimental results show that Our technique works well in extracting the crown shapes of real trees.