Official AI Planner version 0.2.4 released

Hi, @haraldger! I've seen this error a few times. Typically, it means one of the earlier planning jobs failed. Are you seeing any other errors? Are you using custom preconditions or custom action effects? That tends to be where these failures crop up.

 

Hmmm. It's hard to tell from this what the issue might be. Can you share the BuildBarracks code, either here or over DM?

 

Without going too much into the details, that array represents the set of states on the horizon of the plan graph which are selected for forward simulation, in which potential actions are computed applied to said states, extending the plan graph. The array should not be empty, however. This particular error is new to me.

Are you able to see any states in the plan visualizer when this error occurs? Is the plan considered complete (check the root state's complete status)?

 

Apologies for the delayed response; I was OOF last week.

That could be it, certainly. There are two causes for states to be marked complete: (1) the termination criteria is fulfilled, or (2) no valid action can be taken in the state. If you look over the actions in you've specified in the plan definition, is there any action whose preconditions are completely satisfied by this state?

 

This is very strange, indeed. Your action definition and state data indicate you should be able to build a barracks at the free building location. It's promising that it worked at an earlier point. When you recreated the project, did you delete the generated code ("AI Planner Plans" and "AI Planner StateRepresentation" in your packages directory) and regenerate it from the authoring assets?

If you're handy with a debugger, you can also try setting a breakpoint in the job code for the action Build Barracks. A great place to start is in the execute method, after the action's valid argument permutations are computed (looking for >1 valid set of arguments).

 

I'd still recommend deleting the generated code for a fresh try. Occasionally, I have come into a situation where I've generated code with some set of preconditions/effects, then change one or more and forget to regenerate, causing issues down the line when the removed (in asset) parts linger in the generated code silently.

Ah. I'll explain what you should look for. Without going too much into detail, given a target state, each action job first computes every valid permutation of action arguments (correct traits, satisfies precondition constraints), then for each permutation generates a resulting state (what the state should be after the action). I suspect your issue is somewhere in this process.

By setting breakpoints in the action job, you should be able to quickly see if any valid argument permutations are found. If valid arguments were not found, the issue is likely at the point of querying the state and checking preconditions (in
GenerateArgumentPermutations(...)). However, if valid arguments exist, the problem is likely in the forward simulation (in ApplyEffects(...)).

 

The AI teams are working on a few new projects, though it's too early to share information on them quite yet. I can confirm that the AI Planner is not part of these new initiatives, though some of the tech and many of the learnings we gained during development are heavily influencing the new tools.

Regarding timing of future announcements on these fronts, I wouldn't expect any public news for six months to a year. Until then, you can track roadmap changes and request new features/tools through the public Unity roadmap portal: https://unity.com/roadmap/unity-platform

 

The best place to provide feedback on tools and features you'd like to see is the public roadmap, linked in my original comment. I'll note that under each sub-area, you can submit ideas/requests in the "Under Consideration" section. Relevant areas to our projects:

https://unity.com/roadmap/unity-platform/navigation-game-ai
https://unity.com/roadmap/unity-platform/3d-characters-and-animation
https://unity.com/roadmap/unity-platform/gameplay-ui-design
https://unity.com/roadmap/unity-platform/dots

 

We can't account for all of Unity's codebase, but if you are using any of our packages (AI Planner, Traits, NavMeshComponents), you can copy the package files to a custom folder and import the package from disk, allowing you to make arbitrary changes to the code.

 

I understand that perspective. I quite enjoy hearing what other people have to say and often learn something in the process. Next time I meet with the relevant persons who manage the public roadmap, I'll raise the issue.

That said, requests and comments made on the public roadmap portal are absolutely seen internally, from product managers operating at the top of the business down to specialized engineers such as myself. It is one of the up-and-coming means of receiving this kind of feedback from our users, and I would encourage its use despite the limitations on discoverability and the one-sidedness of the input.

Of course, also keep having discussions here in the forums too.

 

Hello, vx4! We're not ready yet to announce or unveil anything just yet. That said, development on our next project has been proceeding quite well, and we are hoping to move from internal to public testing in the first half of 2023. We'll make an announcement here as soon as it's ready.

 

Sorry for the prolonged silence, everyone. As you may know, there have been many changes at Unity over the past year, which has unfortunately impacted our proposed release path and timeline. Despite our project's development staying on track, we've been asked to bump the experimental release to the fall, with an associated presentation at Unite 2023 in November.

My team is still hard at work on the new tool, which will target gameplay and behavior, much like the other tools we've worked on over the years. While we're waiting for the eventual release, we've been packing in as many QoL, user-friendly UX, and cutting edge experimental features as we can. I admit this all is quite vague. I wish I could provide more details, but until we have comms approval, it's going to be quiet here for the time being.

 

It will target GameObject workflows initially but should be compatible with hybrid ECS projects. We're in talks with the relevant teams about the potential for a pure DOTS backend, but until we have sufficient demand and investment for that path, it will likely remain a desired feature more than a committed one.

 

I wish I had the time to attempt an update, but the truth is we're a little understaffed and have our hands full at the moment. I'm sorry to disappoint.

I can confirm it is not utility AI, though I wish we could develop a package for it. I have yet to find a 3rd party utility AI system that I would recommend highly.