Custom visualizations in machine holograms example from Beaver

modules/ROOT/pages/Development/Satisfactory/BuildableHolograms.adoc

@@ -502,3 +502,44 @@ bool AMyModHologram::TryUpgrade(const FHitResult& hitResult)
 	return Super::TryUpgrade(hitResult);
 }
 ```
+
+== Showing Additional Visualizations
+
+Blueprint Machine Holograms can spawn custom visuals to assist the user with placement of some buildable objects.
+Using a custom visualization replaces the default visualization.
+This approach is commonly used when a custom buildable requires extra settings and configuration to look correct.
+Consider the following example:
+
+```cpp
+void FMyModModule::StartupModule() {
+	AFGBlueprintHologram::FCreateBuildableVisualizationDelegate visualizingDelegate;
+	visualizingDelegate.BindLambda([](AFGBlueprintHologram* blueprintHologram, AFGBuildable* buildable, USceneComponent* buildableRootComponent) {
+		// Get your buildable
+		AMyBuildable* myBuildable = Cast<AMyBuildable>(buildable);
+
+		// - your cool code here for all the relevant components-
+		// likely involves referencing stuff myBuildable
+		// note that the buildable reference is only scoped to this lambda so don't expect it to persist
+
+		// example: if we had one custom spline mesh component to show it might look like this:
+		USplineMeshComponent* splineMesh = Cast<USplineMeshComponent>(
+			// we use the built in setup component so we don't have to worry about things like: attaching to the actor, transformations, mobility, customizer data, hologramFX, collision channels, and more you would need to set manually if you didn't
+			blueprintHologram->SetupComponent(
+				buildableRootComponent,
+				buildable->GetComponentByClass<USplineMeshComponent>(),
+				buildable->GetFName(),
+				FName()
+			)
+		);
+
+		// example: now do the configuration the vanilla configuration won't, since we are using a custom one
+		splineMesh->SetStartPosition(curve->StartPosition, false);
+		splineMesh->SetEndPosition(curve->EndPosition, false);
+		splineMesh->SetStartTangent(curve->StartTangent, false);
+		splineMesh->SetEndTangent(curve->EndTangent, false);
+		splineMesh->UpdateMesh_Concurrent();
+	});
+
+	AFGBlueprintHologram::RegisterCustomBuildableVisualization(AABCurvedDecorBuildable::StaticClass(), visualizingDelegate);
+}
+```