Missing steps in Introduction to AI with Blueprints on the Unreal Learning site

Development Programming & Scripting AI
1

I’m going through the Introduction to AI with Blueprints at Ooops! Invalid access and ran into a snag. I’m looking for advice on how to fill in this gap.

The training gets to three modules

  • Behavior Tree Theory
  • Building the Initial Behavior Tree
  • Chasing the Player

In the Building the Initial Behavior Tree module, you create and rename the initial Behavior Tree, you create and rename the initial BlackBoard and ensure that the BlackBoard asset points to BB_EnemyAI. In the Behavior tree, He has you click on NEw Task and select the BTTask_Blueprint_Base… you go into the BP editor but then you switch out to “organize the folder structure” when he returns from that he’s in a different task called BTT_FindNavigableLocation. He walks you through creating the blueprint for this task’s eventgraph. After this step is done, you compile and save and close the blueprint window and come back to the Behavioral Tree and it’s got an entire sequence laid out. BT->Sequence->Random Wander which connects to “Find Suitable Location”, “Move To”, and “Wait”. Where did all this come from? It feels like several steps were just skipped here.

In the Chasing the Player module, it starts with these nodes also already present in the Blueprint Tree and I don’t feel I can continue with the module.

Thanks! Currently DLing UE 4.22.3 because the sample project for this training starts with numbers and … 4.24.2 doesn’t support that. Grrrr. :slight_smile:

-MM

2

I’ve found that some of the Unreal Engine training videos from the website are buggy and there is no place to ask questions for the trainer. It’s frustrating to invest so much time on a dead-end tutorial. I couldn’t get the RandomWander custom event to work in this tutorial, although it does work in the demo project. So disappointing.

3

Hi, I see those videos as learning videos, not step by step tutorials (In my opinion there was way too much step by step in the AI learning video and it only concentrated on the very basics, so basically retold the quickstart guides, instead of talking about workflow and performance considerations and explaining the nodes available).

So you might wanna follow the behavior tree quickstart guide step by step Behavior Tree Quick Start Guide | Unreal Engine Documentation

Quickstart guide for EQS: Environment Query System Quick Start | Unreal Engine Documentation

And doc on AI Perception: AI Perception | Unreal Engine Documentation

4

Hi, I am fairly new to Unreal Engine, but I would go with JediMaster108. The summary of the lecture told us, that we have learned building the behaviour tree in this lesson. But this content was not in the lesson video. It would be great if the sources chrudimer has listed here are part of the course.

5

I didn’t even get this far. I am stuck on the NavMesh Agents module. I followed through the steps (I think) and then the AI doesn’t move? Anything obvious I might have missed here, he seems to go through step by step which i’m finding useful but I can’t see where I might have missed anything (I’m guessing maybe something wrong with my NavMesh?

6

Hi, @JabbaKITE you might wanna follow those quickstart guides I posted a link to above, there the basics are explained step by step.

Basically for your AI to move on the navmesh, you need to have a navmesh, the AI needs to be possessed by an AI controller, and you would have to call a “Move To” node and then the AI needs to have a valid way to the target location.
For debug I find it useful to have one AI in the level and then watch the behavior tree (the variables and the execution flow) while the game is running (so you would need to run the game in PIE, not standalone).

Also you can visualize the area the navmesh is covering by pressing P Navmesh Content Examples | Unreal Engine Documentation

7

@MOFOMOJO ~ I’m doing the same course and came to this same issue. What a bummer. Guess I will stick to random You Tube videos to figure it out.

8

Hey! I got stuck here today too, and after 3-4 hours of troubleshooting, I determined that my Blueprint was fine, but my whole Level was somehow the broken element – not the navmesh or anything else. I could import MY elements into the example, but theirs would break in my (vanilla) Level.

So I copied their level into my Project, and added my BP characters… everything was fixed!

9

Hello! I am also interested in these questions, if you found the answers, please write to me!

10

Check out the ActionRPG project. They use behavior trees and you can study every BT service they made and how it is used in their trees as well as in game for testing purposes.

It’s not a tutorial video, but I found it more helpful to learn from an already working one.

11

I am not sure if you are facing the same problem as me, but for me too the AI was not moving. And then I deleted the Recast Nav Mesh and rebuilt all paths, and then it seemed to work. Original source to answer here: Simple Move To Actor not working for Ai Controller - #16 by Jacob777

Maybe give that a shot?

12

This video fills in the missing material: