I realized that the imitation learning loss you used in the code base is essentially the cross entropy loss between the predicted action and the oracle action which is obtained by selecting the closest waypoint to the goal. However, this oracle action might not be optimal because sometimes the closest waypoint may not be on the ground truth path (reference path in the dataset). like the following pic,
It is likely to cause the agent to loop around the area.
As the waypoint predictor shows very good results, I wonder if you can comment on how the waypoint predictor manages to avoid the above issue.
Hi Yicong, thanks for releasing the code of the Discrete-to-Continuous work. I have been reading papers in the VLN field, including the recent VLN-CE. There is one detail that confuses me for long after reading papers related to VLN-CE. I found that in discrete VLN, almost all recent works adopted a mixed IL + RL training strategy for better performance. However, most later works in VLN-CE instead turned to a simpler IL training scheme without any RL, including your Discrete-to-Continuous work. I wonder why researchers gave up the effective IL+RL strategy. Is it just a conventional choice following the first VLN-CE work or there are some other reasons? I really appreciate it if you can share your thoughts.
I have been reading your paper lately and looking at the code to try to reproduce the experiment. In ss_trainer_VLNBERT.py, 0 action (stop) or 4 action (HIGHTOLOW) at the end of each step is performed through env.step. Can you explain why? And can you tell me what action HIGHTOLOW is? Is it an act of lowering the perspective from the top down?
Thanks for releasing the code of the dcvln, it is an very interesting job. I follow the instruction to run the source code, it works perfectly. But when I want to debug the code by Pycharm 2018 Pro, it gets stuck in self.envs = construct_envs( self.config, get_env_class(self.config.ENV_NAME), episodes_allowed=episode_ids, auto_reset_done=False ) in ss_trainer_CMA.py line 361, which is very weird.
Specifically, I use the Debug in Pycharm IDE and run the code step by step, it always gets stuck in this line and no response at all.
I guess the problem is due to the multiprocess, maybe certain subprocess is wait for interaction or something. I tried to go inside and found habitat.VectorEnv() is no response. Possibly, is it the problem of our computer or IDE? Does debug mode work well in your side?
I'm looking for your reply!