How to combine vector of 2D mat into a 3D mat ? Or

How to combine vector of 2D mat into a 3D mat ? Or how can i directly fill up a 3d mat with 2d mats ? This is my code but its not working int planSize[] = { 48, 49, 49 }; cv::Mat voxel(3, planSize, CV_64FC1); for (int i = 0; i < 48; i++) cv::filter2D(imageGray, voxel[i]), -1, texture[i]);