And,what's the differences between the ORB_SLAM2_modified and the orbslam2_modified.zip?

@melodybinbin Have you figured it out? I also saw that the point cloud has no cloud rendering. I modified some code, but did not succeed.

@gaoxiang12 Could you please help us with this issue? Thanks.

Thank you, please use the code in "ORB_SLAM2_modified/" directory, not the zipped file. It is an earlier version and I don't have time to clear it now.
About the problem that the viewer doesn't show point cloud's color, please check if ORB SLAM has converted the RGB images into grayscale ones. Check the reading parts in System.cc and Tracking.cc and if so, change those codes to make the point cloud can really read the color.

Thanks, that solved my problem.

@CTTC I have met the same problem. The pointcloud has no color information. How you solve the problem? Can you give me a help?

I have this problem too, I remember it's color in the past. But in that version, I must install g2o_with_orbslam2, it's in zipped file. I would not to install the past version because that g2o version is different with now.

@CTTC I have met the same problem.The color of dense pointcloud map is black and white,without color information.Can you give me a help? Thankyou

As Dr. Gao said above, use the code in "ORB_SLAM2_modified/" directory, not the zipped file.
Firstly, declare mImRGB in Tracking.h as following:
Frame mCurrentFrame;
cv::Mat mImRGB;//declared
cv::Mat mImGray;
Secondly, modify the Tracking.cc as following:
Modified place 1:
cv::Mat Tracking::GrabImageRGBD(const cv::Mat &imRGB,const cv::Mat &imD, const double &timestamp)
{
mImRGB = imRGB;//Modified place 1
mImGray = imRGB;
......

Modified place 2:
mpPointCloudMapping->insertKeyFrame( pKF, this->mImGray, this->mImDepth );//change the mImGray to mImRGB as next row
mpPointCloudMapping->insertKeyFrame( pKF, this->mImRGB, this->mImDepth );//Modified place 2

Finally,execute build.sh and build_ros.sh to realize color dense pointcloud map with data sets and kinect v2 respectively.