Duplicate Actor Child Static Mesh Components Lingering

[ericatomes]

Hi All. Here is the scenario. I have an AActor which I like to show some special static mesh component and text render components for in editor only. Basically the Actor has an array of FVectors that can be manipulated in the editor and for each point in that array I create a static mesh component and text render component (for visualization).

The problem comes in when the actor gets duplicated via alt+drag or copy+paste. Upon duplication, the new actor has all of the static mesh and text render components as the original actor but then when I go to move one of the points in the new actors’ array the “old” static mesh and text render component linger in the editor view. If I reload the level OR recompile the parent blueprint of the actor then those old static mesh and text render components are removed. Any ideas on why this might be happening?

In order to refresh the static mesh and text render components I am hooked into PostLoadSubobjects and PostEditChangeProperty. The logic of these functions is that I destroy my array of static mesh and text render components and then recreate based off of the array of FVector data on the class, so don’t think there’s any issues there.

I have posted a series of images. The first image shows that I have duplicated the actor (new actor is selected). The second image shows that I have now manipulated one of the duplicated actors’ points and you can see two static mesh and text render components (bad state). The third image shows what happens after reloading the level and/or recompiling the parent blueprint, the old static mesh/text render component has been removed (good state, what I would have expected in image 2 if everything was working correctly).

Thanks.

[ericatomes]

I was able to solve this. Alright so stepping through the engine code it seems that the code that copies properties over from the original actor will first copy all components attached to the root component and then copy over all other properties.

In my case I had setup attachment on the static mesh components and text render components to the Root Component. So whenever it was going through and creating the new actor, it would first copy all those components attached to root and then it would copy the components in my array (so it happened twice). And of course whenever I would manipulate my points in the array it would just update the static mesh/text components that were copied during the array copy part and NOT the ones that copied over as a result of traversing the root component.

In order to mitigate this, I had to override PostEditImport() function to remove those extraneous components. Simply setting up a different attachment didn’t work. I suppose it must traverse children of children of the root component.