如何使用 OpenMesh 设置人脸的颜色?
How to set the color of a face using OpenMesh?
我正在尝试设置某张脸的颜色,但我的代码一直出错。
行 mesh.set_color(*f_it, clr);
抛出错误(关于 属性 错误)。我尝试将其更改为 mesh.set_color(f_it.handle(), clr);
,但这会引发取消引用错误。
我要正确设置颜色吗?
typedef OpenMesh::TriMesh_ArrayKernelT<> myMesh;
myMesh * Mesh;
myMesh mesh;
void computeFaceNormals(myMesh mesh) {
OpenMesh::Vec3f pointA, pointB, pointC;
myMesh::VertexIter vlt, vBegin, vEnd;
myMesh::ConstFaceVertexIter cfvlt;
myMesh::Color clr;
for (myMesh::FaceIter f_it = mesh.faces_begin(); f_it != mesh.faces_end(); f_it++) {
cfvlt = mesh.cfv_iter(*f_it);
pointA = mesh.point(*cfvlt);
pointB = mesh.point((*cfvlt++));
pointC = mesh.point((*cfvlt++));
clr[0] = 0;
clr[1] = 1;
clr[2] = 0;
mesh.set_color(*f_it, clr);
}
}
openmesh 网格 (OpenMesh::TriMesh_ArrayKernelT
) 可以使用 不同的属性:顶点颜色、面颜色、顶点法线等。但是您需要明确指定您希望网格具有的属性。
在你的情况下,你缺少的是
mesh.request_face_colors();
如果您收到网格作为参数,您可以检查它是否已经具有颜色属性:
mesh.has_face_colors()
您还可以使用以下方法删除属性:
mesh.release_face_colors();
Read the tutorial for more details. 您应该考虑的重要说明(来自教程)阐明了 request/has/release:
的用法But, what happens if for example the vertex status property has been requested twice? Then the first release does nothing, but the second one will remove it. The standard properties have a reference counter, which is incremented by one for each request and decremented by one for each release. If the counter reaches 0 the property will be removed from memory.