Scannable Objects

BPC_Scannable 📸🔍

The BPC_Scannable component extends the Selfie Cam system by allowing specific actors in the world to be "scanned" whenever a screenshot is taken. This makes it possible to tag screenshots with contextual metadata about visible objects — such as quest items, characters, or interactables.

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System Overview 🛠️

When the BPC_Scannable component is attached to an actor, the Selfie Cam performs the following checks:

1. Bounding Box Generation 📦

   • The component collects the actor’s visible primitives (Static Mesh Components, Skeletal Mesh Components, etc.).

   • A bounding box is created around these primitives.

   • The system samples points across this bounding box (center, corners, etc.) to use for visibility testing.

2. Camera Frustum Test 🎥

   • The bounding points are projected into screen space.

   • If the required number of points are inside the active camera frustum, the actor is considered visible.

   • By default:

     • Scan Range = 1000 units

     • Required Points = 1 (i.e. only one point needs to be inside the camera view).

3. Optional Line Trace Validation 🎯

   • If Line Trace Bounding Points is enabled, each point is validated with a line trace:

     • The trace runs from the camera position to the bounding point.

     • If the line is blocked, the point is considered occluded.

     • You can:

       • Ignore specific actors using a tag.

       • Ignore specific component classes under Advanced > Component Classes to Ignore (defaults include Niagara systems, Groom components, widgets, nameplates, and others).

If an actor passes all checks, it is marked as scanned for that screenshot.

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Metadata Inclusion 🗂️

Once an actor has been successfully scanned:

• Its metadata is attached to the screenshot payload.

• This data is passed to the On Screenshot Taken delegate on the Player Character’s BPC_ODK_ScreenshotComponent.

• Example flow:

  • Player presses IA_SelfieMode_TakeSnapshot.

  • Screenshot is saved locally and minted.

  • Delegate fires → returns metadata including any scannable actors in view.

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Customization ⚙️

The BPC_Scannable component exposes several options for tailoring how actors are scanned and represented:

Scan Parameters

• Scan Range (float) → Maximum detection distance from the camera (default: 1000).

• Required Points (int) → Number of bounding box points that must be inside the frustum (default: 1).

• Line Trace Bounding Points (bool) → Enables occlusion checks for more accurate results.

Metadata

• Friendly Name (FString, Exposed Variable)

  • If set, this is included in the screenshot’s metadata JSON.

  • If not set, a fallback name is auto-generated from the actor’s name.

• GetScanInfo Override 🔧

  • Developers can subclass BPC_Scannable and override the GetScanInfo function.

  • This allows returning a custom JSON object with arbitrary fields.

  • Example: rarity, quest state, or any game-specific attributes.

Bounds Modifiers

• Origin Modifier (FVector) → Shifts the generated bounds center.

• Extent Modifier (FVector) → Expands or shrinks the generated bounds extents.

• Useful for fine-tuning where an actor’s scannable area is relative to its meshes.

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Example Workflow 🚀

1. Setup

   • Attach BPC_Scannable to any actor you want to be detectable in Selfie Cam mode.

2. Configure

   • Adjust Scan Range and Required Points to match how “strict” the scanning should be.

   • Enable Line Trace Bounding Points if you need occlusion accuracy (e.g. actors behind walls shouldn’t be detected).

3. Take Screenshot

   • Player enters Selfie Mode (IA_ScreenshotCamera_Toggle).

   • Camera checks for nearby scannable actors.

   • If visible, bounding box points pass frustum/trace tests → actor metadata is collected.

4. Handle Metadata

   • When the screenshot is taken, the On Screenshot Taken delegate on BPC_ODK_ScreenshotComponent fires.

   • This delegate returns:

     • The screenshot image data.

     • Any attached metadata from scannable actors.

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👉 With this system in place, screenshots taken by players don’t just capture visuals — they also capture contextual metadata about the world, making them perfect for collectibles, quests, or social sharing features.