Question

我正在使用C ++中的OpenMesh库。我有一个函数，无论边是凹还是凸，都应该返回。

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其中函数angleBetweenVectors（Vec3f，Vec3f）实现为

bool isConcave(HalfedgeHandle initial, Mesh & mesh){ FaceHandle face1 = mesh.face_handle(initial); FaceHandle face2 = mesh.face_handle(mesh.opposite_halfedge_handle(initial)); long double angle = angleBetweenVectors(mesh.calc_face_normal(face1), mesh.calc_face_normal(face2)); if (angle >= (M_PI/2)){ cout << "Convex " << (angle * RADIANS_TO_DEGREES) << "\n"; return false;} else{ cout << "Concave " << (angle * RADIANS_TO_DEGREES) << "\n"; return true;}}

但是当我在OpenMesh上的tutorial中构建的立方体的各个边缘上运行它时，我的输出为“凹面0”和“凸面90”，此时所有边都应该是凸面90.为什么是我的输出不正确？

Answer 1

好吧，万一其他人想知道，因为我意识到了这个问题......

立方体是三角形网格。因此，立方体的每个面实际上被分成两个三角形面。因此，某些面在技术上是平行的，这些面之间的角度为0度。

如何确定边缘在3d中是凹还是凸？

1 个答案: