ORB-SLAM3 单目运行EuRoC数据集没有显示图像

运行

./mono_euroc

后，没有图形界面，只显示了：

num_seq = 1
Loading images for sequence 0...LOADED!

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ORB-SLAM3 Copyright (C) 2017-2020 Carlos Campos, Richard Elvira, Juan J. Gómez, José M.M. Montiel and Juan D. Tardós, University of Zaragoza.
ORB-SLAM2 Copyright (C) 2014-2016 Raúl Mur-Artal, José M.M. Montiel and Juan D. Tardós, University of Zaragoza.
This program comes with ABSOLUTELY NO WARRANTY;
This is free software, and you are welcome to redistribute it
under certain conditions. See LICENSE.txt.

Input sensor was set to: Monocular
Loading settings from /home/changym/slamsource/ORB_SLAM3/Examples/Monocular/EuRoC.yaml
Camera1.k3 optional parameter does not exist...
	-Loaded camera 1
	-Loaded image info
	-Loaded ORB settings
Viewer.imageViewScale optional parameter does not exist...
	-Loaded viewer settings
System.LoadAtlasFromFile optional parameter does not exist...
System.SaveAtlasToFile optional parameter does not exist...
	-Loaded Atlas settings
System.thFarPoints optional parameter does not exist...
	-Loaded misc parameters
----------------------------------
SLAM settings: 
	-Camera 1 parameters (Pinhole): [ 458.65399169921875 457.29598999023438 367.21499633789062 248.375 ]
	-Camera 1 distortion parameters: [  -0.28340810537338257 0.073959067463874817 0.00019359000725671649 1.7618711353861727e-05 ]
	-Original image size: [ 752 , 480 ]
	-Current image size: [ 600 , 350 ]
	-Camera 1 parameters after resize: [  365.94735717773438 333.44500732421875 292.99069213867188 181.10678100585938 ]
	-Sequence FPS: 20
	-Features per image: 1000
	-ORB scale factor: 1.2000000476837158
	-ORB number of scales: 8
	-Initial FAST threshold: 20
	-Min FAST threshold: 7


Loading ORB Vocabulary. This could take a while...
Vocabulary loaded!

Initialization of Atlas from scratch 
Creation of new map with id: 0
Creation of new map with last KF id: 0
Seq. Name: 
There are 1 cameras in the atlas
Camera 0 is pinhole
First KF:0; Map init KF:0
New Map created with 271 points

打开mono_euroc.cc查看，第83行

// Create SLAM system. It initializes all system threads and gets ready to process frames.
    ORB_SLAM3::System SLAM(argv[1],argv[2],ORB_SLAM3::System::MONOCULAR, false);

这里的4个参数初始化了SLAM 系统，可以查看头文件System.h来了解其含义。在第105行：

    // Initialize the SLAM system. It launches the Local Mapping, Loop Closing and Viewer threads.
    System(const string &strVocFile, const string &strSettingsFile, const eSensor sensor, const bool bUseViewer = true, const int initFr = 0, const string &strSequence = std::string());

可见这里的第四个bool型参数为bUseViewer，表示是否使用可视化。
所以，将mono_euroc.cc中的第83行false改为true，然后重新make编译即可展示可视化界面：