fiinal_results = "Marker not found in the output"

[PopeyePxx]

Thank you for your kind words! I am using Ubuntu 18.04 and compiling GPD with the command find_package(PCL 1.8 REQUIRED), and when running python realbot_ui.py -m outputs/example_data, I encounter the following error:
Global grasps generated
0 grasps generated
Traceback (most recent call last):
File "/home/hun/anaconda3/envs/grasp_splats/lib/python3.10/site-packages/viser/infra/_infra.py", line 449, in wrapped
inner()
File "/home/hun/anaconda3/envs/grasp_splats/lib/python3.10/site-packages/viser/infra/_infra.py", line 257, in
lambda: self._handle_incoming_message(client_id, message)
File "/home/hun/anaconda3/envs/grasp_splats/lib/python3.10/site-packages/viser/infra/_infra.py", line 94, in _handle_incoming_message
cb(client_id, message)
File "/home/hun/anaconda3/envs/grasp_splats/lib/python3.10/site-packages/viser/_gui_api.py", line 157, in _handle_gui_updates
cb(GuiEvent(client, client_id, handle))
File "/home/hun/code/GraspSplats-main/realbot_ui.py", line 399, in _
global_grasp_scores_visual = (global_grasp_scores_visual - np.min(global_grasp_scores_visual)) / (np.max(global_grasp_scores_visual) - np.min(global_grasp_scores_visual))
File "<array_function internals>", line 200, in amin
File "/home/hun/anaconda3/envs/grasp_splats/lib/python3.10/site-packages/numpy/core/fromnumeric.py", line 2946, in amin
return _wrapreduction(a, np.minimum, 'min', axis, None, out,
File "/home/hun/anaconda3/envs/grasp_splats/lib/python3.10/site-packages/numpy/core/fromnumeric.py", line 86, in _wrapreduction
return ufunc.reduce(obj, axis, dtype, out, **passkwargs)
ValueError: zero-size array to reduction operation minimum which has no identity

I discovered that this error is because during the sample_grasps process, it cannot recognize the marker "FINAL RESULTS FOR PYTHON:\n". When I print the output, it does not contain this marker.

Here is the relevant code snippet:
command = [binary_file_path] + arguments
result = subprocess.run(command, capture_output=True, text=True)
output = result.stdout

Could you please explain why this is happening? Thank you very much!

[jimazeyu]

Because of "0 grasps generated", if there's any grasp found, then there should not be an error

[PopeyePxx]

Thank you for your quick response. However, no matter how I query the object, the resulting grasp is always 0. It's the same even when I use the default text as you set. So, I took a look at why this is happening, and I pinpointed the issue to the result. When I print it out, it doesn't contain the content marked by marker = "FINAL RESULTS FOR PYTHON:\n". Could you please help me understand why this is happening?

def sample_grasps(pcd_file_path, if_global=True):
binary_file_path = "/home/hun/code/GraspSplats-main/gpd/build/detect_grasps"
if if_global:
arguments = ["/home/hun/code/GraspSplats-main/grasp_cfg/gpd_params_global.cfg", pcd_file_path]
else:
arguments = ["/home/hun/code/GraspSplats-main/grasp_cfg/gpd_params_local.cfg", pcd_file_path]
command = [binary_file_path] + arguments
result = subprocess.run(command, capture_output=True, text=True)
output = result.stdout
marker = "FINAL RESULTS FOR PYTHON:\n"
start_index = output.find(marker)

[roboyike]

I have the same problem. It seem like gpd can't generate any grasp

[AmolKodange12]

Hey @PopeyePxx and @roboyike ,

I was struggling with this error for sometime and finally found why it's happening:

If you cloned and built gpd like I did following the readme, from the original repo , it would not contain changes made by the author which add the code for returning the grasp candidates and adding the marker which would be used downstream by grasping_utils.sample_grasps() for processing and generating the grasps.

Specifically this part in detect_grasps from lines 82-99

  // Detect grasp poses.
  std::vector<std::unique_ptr<candidate::Hand>> hands = detector.detectGrasps(cloud);

  printf("FINAL RESULTS FOR PYTHON:\n");

  for (int i = 0; i < hands.size(); i++) {
    hands[i]->print();
  }

Simply replacing the original lines and building it with cmake and make worked for me :)

Hope it works for you too.

Kind regards,
Amol Kodange