IMGD 4000

Details

You are to extend the QuickStart First-Person Shooter as follows:

(Note: If you prefer to start with a fresh project, rather than the First-Person Shooter, that is also fine.)

• Add waypoints that are placeable using the UE4 Level Editor. These are the nodes for the A* algorithm.

• Establish connections among the waypoints. These are the edges for the A* algorithm.
  • One option is that each waypoint automatically connects to nearby waypoints when it is created.
  • Another option is for connections to be manually specified either in the editor.
  • Connections should have a cost, either implicit based on distance in the world model or a separately entered number (e.g., to represent the material along the connection).

• Provide a way to select any two waypoints as the source and destination nodes for pathfinding. The source node could, for example, default to the node closest to the player.

• Compute the path from source to the destination using A*. There are many Internet sources that describe A*, including slides from IMGD 3000, but all code written must be your own.

• Depict the path visually in some fashion. At the very least, the path should be displayed in text form (e.g., using AddOnScreenDebugMessage()). Better would be to display the path using colored lines in the world.

Successful completion (and demonstration) of the above steps is sufficient for a "B" grade.

To achieve an "A" grade, add simple waypoint path smoothing as presented in class. Note, you also must implement some obstacles to smooth "around" in this case.

You should be prepared to demo your solution, including your extension for an "A" grade (if any), as well as answer questions about your code and implementation.

You will work alone for this project. You may discuss this project with others, but you must write all the code yourself.

Debugging Hint: To get extra debugging control, such as breakpoints, see instructions for how to attach Visual Studio to the Unreal Editor process.

Hints

Waypoints are easiest to extend from the Actor. Having a visible element, such as a sphere, will make them viewable in the level editor.

You are strongly encouraged to check out the tutorial "Making Waypoints in UE4"). This walks you through creating Waypoints that are visible in the Level Editor, while allowing C++ code to be written for the A*.

Important! Accessing the Blueprint PathNode's "nextNode" variable from C++ is possible, but not advised. An alternate waypoint implementation is to create a PathNode C++ class and then create a Blueprint that inherit's from that class. If you create attributes in the C++ PathNode and prefix them with:

UPROPERTY(EditAnywhere, BlueprintReadWrite)

Lines between the waypoints, including the computed path, can be shown with DrawDebugLine():

  static void DrawDebugLine (
    UObject *WorldContextObject,
    const FVector LineStart,
    const FVector LineEnd,
    FLinearColor LineColor,
    float Duration,
    float Thickness
  );

For example:

  // Draw a red line.
  FVector start(0.0, 0.0, 0.0);
  FVector end(0.0, 10.0, 0.0);
  DrawDebugLine(GetWorld(), start, end, FColor::Red, 1.0, 12);

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