Destructible Sphere - Bug

Development Programming & Scripting
1

I am trying to fracture a sphere that is hollow inside.

Example:
Like an egg. Only instead of being thin, the eggshell would be thick. That’s what I’m doing with a sphere.

However, unfortunately the editor is unable to finish calculating the result. You spend a lot of time calculating and it never ends. The editor appears in the status: Not responding. I’m waiting, but I can’t do anything. I need to end the process in order to close the editor and open it again to be able to use it.

This is a bug. All other types of formats are fractured correctly, except this one.

Would there be a solution?

I appreciate the help.

Sincerely, HighRender.

2

This is a bug. All other types of
formats are fractured correctly,
except this one.

I’ve created this static mesh out of brushes and it seems to work OK:

Image from Gyazo

And an fbx one, exported from 3ds Max:

Image from Gyazo

This one is 1500 triangles and took around 10s on a modest CPU.

Have all your meshes been exported in the same way?

3

UE 4.18

We’re 7 versions apart - that’s nearly 3 years of bug fixing. So maybe it’s a bug. But you can’t expect support for an old engine version.

4

Thanks for the help!

My processor is a Ryzen 7 2700x. In short, he does everything quickly in Unreal. It creates fractures in less than 2 seconds, depending even faster than that.

I believe my mesh is quite heavy. I’m going to do some tests on exporting the file and see if anything changes.

“I always thought that when bugs were found in previous versions of UE4, people would make updates.”

I’ll be back with the result later!

Sincerely, HighRender.

5

“I always thought that when bugs were
found in previous versions of UE4,
people would make updates.”

The bug fix update ends up being in the next (if you’re lucky) version, not the version the bug was found on!

Your CPU is not the issue here. It’s either an old system bug in UE4 or the FBX exporter is doing something the engine cannot cope with.

6

Did you adjust any of the fracture settings? 18mins sounds a bit extreme, you’re a patient bear!

I remade my work without changing the
UV and it worked.

Wouldn’t never thought of blaming the UVs but here we are. Thanks for sharing.

7

Yes. I already understood.

Maybe I did something wrong with the UV map. I remade my work without changing the UV and it worked.

It took an incredible 18 minutes to finish loading the new mesh fractures.

The mesh has about 7 thousand triangles. It has a radius of 150cm.

Maybe I made a mistake.
Do you think the time it took to load all of this is normal? Was that expected?

I appreciate your help.

Sincerely, HighRender.

8

I’ve just run a couple of tests and fracturing a 10k tris convex mesh with 7 material slots into 25 chunks (default) takes a second or two on a slower CPU than yours. And pretty much the same on a CPU that is much faster than yours - does not seem to make much difference.

When it comes to fully hollow meshes - that takes more than 10x as long for some reason. Even that simple egg above locks my systems for 10s. ¯_(ツ)_/¯

18 mins sounds a tad excessive. Not sure what to say.

9

Hello!

I ended up forgetting to give an answer.

So far I don’t know why it took so long, but I have my chances of what happened.

My RAM memory is not very big, at least that’s what I think. I only have 8GB. Another point that may have favored is that the sphere was 3 meters high. My paging file was over 16GB and the file was 12GB in use. I think I found the likely reason.

Sincerely, HighRender.

10

Sounds plausible, actually. Swap file is slow even if it’s on an SSD.