Is it possible to filter out scenes without a particular object?

[antonilo]

I am wondering whether is possible to filter out scenes / episodes if a particular category of objects (e.g. stairs) is absent. I assume that the configuration file has to be changed, but I did not find any evident way to do it. Moreover, I am not entirely sure what the difference between scene, state and episode is. Could you please comment on it?

Thanks a lot in advance!

[msavva]

Hi @antonilo, thank you for trying out MINOS.

You can perform this sort of filtering by using code similar to the example given in https://github.com/minosworld/minos/issues/22#issuecomment-387626308 to obtain the categories of all objects present in a scene and then check against the category you want to ensure is absent.

With regards to the terminology, here are some brief definitions that hopefully clarify a bit:

• Scene: a particular 3D environment identified by a scene id (e.g., a particular SUNCG house)
• Episode: A single agent "trial" at performing a task that ends with success or failure. In the context of simulator configuration, this refers to the combination of agent and environment starting configuration and target goal specification (e.g., a 500 step long attempt at reaching a chair in a bedroom, starting from an adjacent bathroom)
• State: The set of agent, environment and task parameters that fully specify the current simulator state (e.g., agent position and orientation). Parts of this state are observable by the agent using sensors, or are otherwise available through metadata/info fields.

[antonilo]

Hi @msavva, thanks for your comment. How can I get all objects that are present in a scene? I guess then I need to regenerate a new state file (as episode_states.suncg.csv) with only the considered scenes, am i right?

I have made a little modification to Roomsimulator.py to change scene if the object is not found. I am basically checking whether there is a path to the goal. Unfortunately this can't be passed as a "scene filter", so I guess performance could be improved. I can make a pull request if that is of interest for you guys.

[msavva]

The code at https://github.com/minosworld/minos/issues/22#issuecomment-387626308 shows an example of how to get all object nodes present in a given scene. You are right that if you want to generate a pre-filtered set of scenes and episodes such that they are guaranteed to not contain a particular object you would do that by creating new scenes.multiroom.csv and episode_states.suncg.csv. The first specifies the scene train/val/test split, and the second specifies pre-sampled episodes in those scenes for val and test runs.

Pull requests with new features are encouraged and highly appreciated!