[QUESTION] "Edge exists" Error when Processing Point Cloud with TEASER Solver

[WuKyrin]

I encountered an "Edge exists" error message while running the TEASER solver on a point cloud dataset in my project. This issue arises under specific circumstances, which leads me to believe there might be a problem with how edges are being processed or identified within the dataset. This dataset is a stl file of femur and the ply file we captured with our RGBD camera of the operating scences of patients.

[arminkmbr]

I get the same error followed by a "Segmentation fault". Did you find a solution?

[LimHyungTae]

It's hard to reproduce your problem. But, one thing I'm curious is how many correspondences are given to TEASER++?

[arminkmbr]

Hi, thanks for your reply. I'm giving about 600 putative correspondences to Teaser. But the segmentation fault only happens for cases with a high noise bound, e.g. above 1. For low noise bounds, the algorithm works as intended. Funnily enough, I get a segmentation fault and the end of the algorithm even after successful registration.

I'd happily give you more detailed information but im not too sure what info to give.

If i run an example in c++ with extreme high noise bound it takes long but it still works.

I using Win 11 with WSL2 on Ubuntu 20.04 with Python 3.6 and PyCharm. Open3d==0.15.2

[LimHyungTae]

Hmmm it's weird, so you mean you only have a problem when you run TEASER++ on Python? Please use gdb and check the lines where the TEASER++ code makes a breakdown.

[arminkmbr]

Hi @LimHyungTae yes only if i run the python examples with high noise bound. if i run c++ even with high noise bound it runs perfectly. as im having issues with vs code and such i started using the python implementation.

im running with os.environ["OMPNUMTHREADS"] = "12" this is the output from gdb:

Starting program: /home/armin/anaconda3/envs/teasertest/bin/python teaserpythonply.py [Thread debugging using libthreaddb enabled] Using host libthreaddb library "/lib/x8664-linux-gnu/libthread_db.so.1". [Detaching after fork from child process 76685] [Detaching after fork from child process 76686] [Detaching after fork from child process 76689] [Detaching after fork from child process 76690] [Detaching after fork from child process 76691] [Detaching after fork from child process 76694] [New Thread 0x7f3509278700 (LWP 76695)] [New Thread 0x7f34dacfd700 (LWP 76696)] [New Thread 0x7f34d9714700 (LWP 76697)] [New Thread 0x7f34d8f13700 (LWP 76698)] [Thread 0x7f34d8f13700 (LWP 76698) exited] [New Thread 0x7f34d39f8780 (LWP 76699)] [New Thread 0x7f34d31f6800 (LWP 76700)] [New Thread 0x7f34d29f4880 (LWP 76701)] [New Thread 0x7f34d21f2900 (LWP 76702)] [New Thread 0x7f34d19f0980 (LWP 76703)] [New Thread 0x7f34d11eea00 (LWP 76704)] [New Thread 0x7f34d09eca80 (LWP 76705)] [New Thread 0x7f34c5ffeb00 (LWP 76706)] [New Thread 0x7f34c57fcb80 (LWP 76707)] [New Thread 0x7f34c4ffac00 (LWP 76708)] [New Thread 0x7f34c47f8c80 (LWP 76709)] [Detaching after fork from child process 76710] [Detaching after fork from child process 76712] [New Thread 0x7f34d8f13700 (LWP 76713)] [New Thread 0x7f34c1586700 (LWP 76714)] [New Thread 0x7f34c0d85700 (LWP 76715)] [New Thread 0x7f34802b2700 (LWP 76716)] [New Thread 0x7f347dab1700 (LWP 76717)] [New Thread 0x7f347b2b0700 (LWP 76718)] [New Thread 0x7f3478aaf700 (LWP 76719)] [New Thread 0x7f34782ae700 (LWP 76720)] [New Thread 0x7f3473aad700 (LWP 76721)] [New Thread 0x7f34712ac700 (LWP 76722)] [New Thread 0x7f346eaab700 (LWP 76723)] TEASER++ Python registration example [Detaching after vfork from child process 76725] [New Thread 0x7f345a74e700 (LWP 76727)] [New Thread 0x7f344beb8700 (LWP 76728)] [New Thread 0x7f344b6b7700 (LWP 76729)] [New Thread 0x7f344aeb6700 (LWP 76730)] [New Thread 0x7f344a6b5700 (LWP 76731)] Starting scale solver (only selecting inliers if scale estimation has been disabled). Scale estimation complete. --Type for more, q to quit, c to continue without paging-- Thread 1 "python" received signal SIGSEGV, Segmentation fault. 0x00007f345cc13f10 in teaser::RobustRegistrationSolver::solve(Eigen::Matrix const&, Eigen::Matrix const&) () from /home/armin/PYTEASER/build/teaser/libteaserregistration.so

[LimHyungTae]

How much large noise bound do you use now? Originally, a 'large' noise bound is not intended; it should be no larger than voxel sampling size (if you conduct voxel sampling as a preprocessing)

[arminkmbr]

Well, im trying to register 2 point clouds from different sources. One pcd is highly accurate extracted from a 3D model and the other is noisy/incomplete reconstructed from SLAM. I have extracted the columns from both point clouds and extracted the center point from each column. Now im trying to register these column center points with all-to-all correspondence. It works very well when I use the same cloud for source and target. I did not get it to work for the cross-source case with noise bound above 2.5. I have around 25 column center points on each pcd.

My idea was to test to increase the noise bound to compensate for the inaccuracies from the SLAM column centers... If I could just get the translation, that would be beneficial and I could do more testing. Maybe i am not not fully understanding the paper yet.

[jingnanshi]

@arminkmbr All-to-all correspondences are going to be difficult for your case with a large number of points. The segfault might be caused by the program using too much memory.