Merge Actors doesn't work with Instanced Static Meshes

Development Asset Creation
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1

This seems very basic, repro:

  1. Create a blueprint that generates some random instances, e.g. like this:

  1. Place it in a scene and try to merge it via Merge Actors

Result: When merging into static mesh, it will ignore any instances and place them at 0,0,0.

Similar report, but from 4.12, can be found [here.][2]

2

There was one more thread on this topic:

And Epic claiming bug is fixed:

3

Yes, that’s my own report :slight_smile: It’s for 4.12, it looks like the first bug (child actors) is fixed, but instanced meshes are still broken.

4

Hey Slavq,

Thank you for the report. I was able to reproduce this behavior and I’ve created JIRA UE-41366 and our developers will be investigating further. Follow that link to monitor the status of the bug report.

As a workaround; do you need to use instanced meshes for what you are doing? You look to be using this blueprint setup to create randomized Static Meshes through the Merge Actor tool. If this is the case, you can use Add Static Mesh Components instead and this issue doesn’t occur.

I know they aren’t as performant but if you are only using this as an editor tool to create Static Meshes, then it shouldn’t be to bad unless you are creating a really large amount of components.

Cheers,

TJ

5

Thank you!
Yes, this is exactly what I ended up doing as a workaround for now :slight_smile:
Cheers!

6

Hey TJ,

Was just taking a look at the JIRA ticket and it seems that it was dispositioned as “by design.” Can you comment on why this is the designed behavior? Seems counterintuitive to me, and makes it harder for those like me who have blueprints to create final meshes but leave them in the world during design in case we want to make tweaks down the line.

Thanks!
Cameron

7

Hey Cameron,

Sorry for the delay.

This is because the current instance static mesh components are not supported in the HLOD / merge actor system by design. However, we are working on another feature that may address this in the future.

8

Was there ever an update on this? You can combine them in a PLI but it would be a lot cleaner if you could simply combine multiple ISMAs into one parent actor with multiple ISM components. I’m trying to reduce actor count with procedurally instanced meshes.

9

rdInst has an “auto instancing” system which works with instances and PLAs etc, combining them into a singleton instance manager at runtime: