Checking for Custom Trace Channel in C++

Development Programming & Scripting C++
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1

Hi everyone,

I’m looking for away to check in C++ if the user entered the appropriate Custom Trace Channel name used in one of the classes. Is there a way to do that?

1 Like
2

Basically you pass in the ECC_GameTraceChannel with the correct index 1 -18, those are the custom ones you defined in the editor

For instance


FHitResult ATracer::DoTrace(FVector start, FVector end) {
	FHitResult result;
	FCollisionQueryParams qp;		
	FCollisionResponseParams resp;
	GetWorld()->LineTraceSingleByChannel(result, start, end, ECollisionChannel::ECC_GameTraceChannel1, qp, resp);

	return result;
}

Would hit the first custom trace channel

Remember to set trace to block for the custom channel on the object that is supposed to be tested against.

1 Like
3

I’m using the ECC_GameTraceChannel ofcourse. I just want to make sure the user is setting up himself with the correct name.

4

Then I guess you could try

5

You can see binding between ECC_GameTraceChannelX & in-editor names in your project’s DefaultEngine.ini . They looks like:

+DefaultChannelResponses=(Channel=ECC_GameTraceChannel1,DefaultResponse=ECR_Overlap,bTraceType=False,bStaticObject=False,Name="MyCustomCollisionChannelName")

Then you can just create a header with

#define ECC_MyCustomCollisionChannelName ECC_GameTraceChannel1
6 Likes
6

how does this even answer the question ?

7

.h

// custom function to check channel name
public:
//#if WITH_EDITOR
	UFUNCTION(BlueprintCallable)
	bool CheckChannelCustom(FName NameToCheck);
//#endif

cpp

needed includes

#include "Engine/CollisionProfile.h"
#include "Engine/EngineTypes.h"
#include "Misc/ConfigCacheIni.h"



//#if WITH_EDITOR
bool ATraceActor::CheckChannelCustom(FName NameToCheck)
{	
	TArray<TSharedPtr<FName>> SharedNames;
	UCollisionProfile::GetProfileNames(SharedNames);		
	TArray<FString> OutMapList;
	
	const FConfigSection* MapListList = GConfig->GetSection(TEXT("/Script/Engine.CollisionProfile"), false, GEngineIni);
	if (MapListList)
	{
		for (FConfigSectionMap::TConstIterator It(*MapListList); It; ++It)
		{
			FName EntryType = It.Key();			
			FString EntryValue = It.Value().GetValue();			
			FString foundName = "";
			if (EntryValue.Contains("ECC_GameTraceChannel")) 
			{				
				FString startSearch = "Name=\"";
				FString endSearch = "\"";
				int32 startVal = EntryValue.Find(startSearch) + startSearch.Len();
				int32 endVal = EntryValue.Find(endSearch,ESearchCase::CaseSensitive,ESearchDir::FromStart,startVal);
				foundName =  EntryValue.Mid(startVal, endVal - startVal);

				if (foundName == NameToCheck) {
					return true;
				}

//				UE_LOG(LogTemp, Warning, TEXT(" foundName %s"), *foundName);
			};						
		}
	}	
	return false;
}
//#endif
8

Use GetcollisionResponseToChannal() In C++.

9

That will not check for a specific channel name.