.Las was not correctly exported.some of the boxes showed in the .las in equal interval.but my ortho was perfectly exported.here i attached some screen scrab.
That looks like areas of insufficient image overlap to me.
Mark has an excellent point, do you have enough overlap in these areas?
Also, it could it be that those specific areas are classified as buildings or man-made and when exporting you did not opt for it?
Could you check on your side?
If this is not the case, please post here the quality report and a screenshot of the RayCloud with the densified point cloud loaded.
In case the overlap is not enough you should set the minimum number of matches to 2 so that the software will need only 3 valid re-projections to create a new point for the densification instead of 3.
Thanks for the comments