Projectile traveling in the correct direction but oriented backwards?

[KingCole32]

I’m currently working on a 3d sidescroller game.
I recently implemented thrown projectiles by taking the location of the actor and mouse, subtracting them to find the vector between the points (for clarity: mouse - actor), zero’ing out the resulting vector’s x value, then passing the vector to MakeFromX. I then pass the resulting rotation to SpawnActor. This, for the most part, works and sends the projectile in the correct direction and at the arc I would expect.

The problem is, the actual projectile is being rotated in odd direction for reasons I can’t seem to understand. First, the object was being launched long-ways forward (versus the tip at either end being forward). I rotated the actual art asset 90 degrees, correctly orienting the projectile when thrown. Now, when enabling the collision mesh on the projectile, I’m seeing that it’s being launched backwards, apparently.

Anyone have any insight into why this is? Is the only recourse I have to be mindful of this behavior when creating projectiles and orienting them properly beforehand? Any help would be appreciated. While I can fix it as described, I’d like to know if I’m (not?) doing something in code that would cause this.

[KingCole32]

I’d hoped this would get a quick answer since there are so many knowledgeable people here on the forum. That not being the case, I can only assume my question was poorly written, so I’ll simplify it here:

Is there some way I should be fixing the orientation of a mesh in code that won’t mess up its rotation when launched via base ProjectileMovementComponent behaviors? Or is the only sure-fire way to fix the item’s orientation to change it in the base art asset?

Adding location rotation doesn’t work because it effects the starting rotation when the item is made, causing it to fly off in the wrong direction. I’ve searched around, but haven’t found other references to this issue, making me believe it must be my implementation that is stupid.

[anonymous_user_683d4c63]

Some screenshots to visualize the problem would be helpful. Also some code snippets on what you actually do to spawn / rotate the projectile.

Other than that: You need to rotate the Mesh -90° on Z. Usually thats all you need to do.

[KingCole32]

Thanks for the response, I’ll take some screenshots when I’m home, then.

The short of the code I have is in the first post, but I could probably remember offhand what was in the “throw” function. The object being thrown only contains a mesh and a ProjectileMovementComponent:

//get all relevant location information
FVector CharacterLocationLocal = GetOwner()->GetActorLocation();
FVector EquipmentLocationLocal = GetActorLocation();
FVector MouseLocationLocal;
FHitResult HitResult;
GetWorld()->GetFirstPlayerController()->GetHitResultUnderCursor(ECC_Visibility, false, HitResult);

if (HitResult.bBlockingHit)
{
MouseLocationLocal = HitResult.ImpactPoint;
}

//calculate the angle of the vector from the equipment to mouse, ignoring the X value
FVector NewVectorLocal = MouseLocationLocal - CharacterLocationLocal;
NewVectorLocal.X = 0;
FRotator SpawnRotationLocal = FRotationMatrix::MakeFromX(NewVectorLocal).Rotator();
SpawnRotationLocal.Pitch, SpawnRotationLocal.Yaw, SpawnRotationLocal.Roll));

AEquipmentProjectile* ProjectileLocal = GetWorld()->SpawnActor<AEquipmentProjectile>(AEquipmentProjectile::StaticClass(), EquipmentLocationLocal, SpawnRotationLocal);

You mean rotate in Maya, in the mesh asset file in unreal, or the mesh in the projectile object? At this point, I’m fine with rotating it and future weapon/projectile meshes in Maya, but I’m slightly concerned that a problem like this might crop up somewhere else if I don’t understand why, exactly, it’s happening now. Also of note, when only being placed in the level, the projectile is oriented in the correct direction.

[KingCole32]

As requested, here is a picture of the current situation:

This is after rotating the projectile 90 degrees in Maya. It’s still being shot backwards, indicated by the collision volume being on the opposite end of the projectile.