Map recorded by ROVIOLI seems very sparse

I'm trying to do dense reconstruction of a room using maplab/ROVIOLI with a Intel Realsense ZR300. ROVIOLI is running fine with the ZR300, but the map that is generated in the end only contains very few keyframes. Maplab fails to detect any loop closures and I don't see how this map could be used to reconstruct a dense map given that there are so few frames either.

This is the recoding I made (by walking up and down the corridor in our lab and doing a few circles in some of the offices)

$ rosbag info hallway3.bag
path:        hallway3.bag
version:     2.0
duration:    10:04s (604s)
start:       Feb 28 2018 17:03:22.89 (1519833802.89)
end:         Feb 28 2018 17:13:27.11 (1519834407.11)
size:        20.7 GB
messages:    341535
compression: none [17991/17991 chunks]
types:       cuckoo_time_translator/DeviceTimestamp [4e34c15f54cbfa3f64408fe764e59ff4]
             dynamic_reconfigure/Config             [958f16a05573709014982821e6822580]
             dynamic_reconfigure/ConfigDescription  [757ce9d44ba8ddd801bb30bc456f946f]
             sensor_msgs/CameraInfo                 [c9a58c1b0b154e0e6da7578cb991d214]
             sensor_msgs/Image                      [060021388200f6f0f447d0fcd9c64743]
             sensor_msgs/Imu                        [6a62c6daae103f4ff57a132d6f95cec2]
topics:      /zr300_node/color/camera_info                     17971 msgs    : sensor_msgs/CameraInfo                
             /zr300_node/color/image_raw                       17970 msgs    : sensor_msgs/Image                     
             /zr300_node/device_time                          120233 msgs    : cuckoo_time_translator/DeviceTimestamp
             /zr300_node/device_time/parameter_descriptions        1 msg     : dynamic_reconfigure/ConfigDescription 
             /zr300_node/device_time/parameter_updates             1 msg     : dynamic_reconfigure/Config            
             /zr300_node/fisheye/camera_info                   18025 msgs    : sensor_msgs/CameraInfo                
             /zr300_node/fisheye/image_raw                     18025 msgs    : sensor_msgs/Image                     
             /zr300_node/imu                                  149309 msgs    : sensor_msgs/Imu

Maplab tells me that there are only 140 nodes in the map:

maplab <hallway3>:/$ ms
Mission statistics: 

Mission 0:                  c3b971e3ffffffff0f00000000000000    Viwls
    NCamera Sensor:         c6a6f6c779e1b09cf49f11629787945c
    IMU Sensor:             c63aecb41babcabc7e1fac37c7cbe7bf
    Vertices:               140                      
    Landmarks:              7807                     
    Landmarks by first observer backlink:                            
    Camera 0:               4740 (g:66 b:4674 u:0)   
    Camera 1:               3067 (g:22 b:3045 u:0)   
    Observations:           32427                    
    Num edges by type:                               
    IMU:                    139                      
    Wheel-odometry:         0                        
    Loop-closure:           0                        
    Distance travelled [m]: 433.511871               
    Start to end time:      2018_03_02_16_28_50 to 2018_03_02_16_28_50
    T_G_M                   unknown

Also, there are only 280 frames in that map:

$ ls resources/raw_images | wc -l
280

This is the resulting track: rovioli_hallway3_track

What am I doing wrong here? Do I have to change the parameters for ROVIO (in rovio_default_config.info)? Or am I supposed to record the /maplab_rovio/T_G_I topic myself?

ethz-asl / rovio

Map recorded by ROVIOLI seems very sparse #155