Changing skeletal mesh changes the follow spline behavior. Why?

ZX_THX · July 25, 2023, 5:53pm

I set up the UE Sporstcar to drive following a spline path. I hit play and it works fine. The car follows the spline as drawn. But if I replace the sportscar skeletal mesh, so the car is different, it messes up the spline following it seems. As the “new car” now doesn’t follow the spline and instead it just kind of slowly spins around tis own axis, deeping the nose down, staying place, instead of following the spline path. I replaced the sportscar with the sedan from the free Vehicle Variety Pack Volume 2, which is also a chaos vehicle. If I go back and change back to the sportscar mesh, it fixes the problem and behaves as expected, following the spline path as before.

Looking online I couldn’t find an explanation to why it’s doing that. If I want the car to look different or replace the mesh, the above is not the correct way of doing it? Or why is it behaving this way? Thanks in advance.

Shunitzo · July 25, 2023, 5:56pm

Hello

Do you use any bone names in your code?

ZX_THX · July 25, 2023, 5:59pm

I don’t believe so. I’m new to UE and followed a tutorial to set it up. But the Event Graph looks pretty simple:

A bone name would be in there, right?

Shunitzo · July 25, 2023, 6:33pm

Go to Vehicle Movement component and compare Bone Names of an old mesh to the new mesh here:

ZX_THX · July 25, 2023, 6:43pm

Thanks!

Yes, the bones have different names between the 2 cars:

And changing the skeletal mesh asset keeps the original bone names it seems.

So what would I need to do to make it work?

Thanks again.

Shunitzo · July 25, 2023, 6:44pm

You already changed them?

ZX_THX · July 25, 2023, 6:45pm

What do you mean? I don’t think I changed anything. But I’m not sure what you mean. I just opened each car in the editor to look at the bones above.

Shunitzo · July 25, 2023, 6:49pm

Are you changing skeletal mesh or you are using different blueprint actor?
On your image you show 2 different blueprints. First one is a standard car. What is second one?

ZX_THX · July 25, 2023, 7:00pm

I’m trying to make the car look different by changing the skeletal mesh here:

Yes, above I show 2 different blueprints. Because I thought I had to open the different blueprints to compare the bone names. The second blueprint is the blue sedan from the free Vehicle Variety Pack Volume 2:

Which is the skeletal mesh I’m trying to load in the standard car.

Shunitzo · July 25, 2023, 7:02pm

Now I understand.
You just need to copy parameters from left image to the right image.
That should do the trick.

ZX_THX · July 25, 2023, 7:05pm

Thanks. Meaning just copy the same bone names? Or also wheel class names?

For the record, what I need or am trying to do is to have the car look different, but use the same follow spline set up. So I don’t have to build the follow spline set up from scratch for every car I want to have driving around the town. But they should all look different, as in different model of cars. But of course, driving on different splines. So I can populate the town with driving cars etc. And even have a few hero cars. But all using the same follow spline set up. Not sure this is the easiest way. but I set one car up and just migrate it to different projects, duplicate etc.

Shunitzo · July 25, 2023, 7:06pm

Copy both

ZX_THX · July 25, 2023, 7:14pm

Ok, I could copy only the bone name. As the wheel class is a drop down menu and I can’t mark it to copy it.

But now the car at least follows the spline. But the wheels don’t spin. Suspension doesn’t work etc. But the blue sedan is a chaos vehicle too.

Shunitzo · July 25, 2023, 7:17pm

You need to select the class from drop menu

ZX_THX · July 25, 2023, 7:25pm

Ah, ok. Thanks. I just tried it. Wheels still don’t spin and suspension doesn’t work.

Shunitzo · July 25, 2023, 7:27pm

Have you changed animation blueprint?

ZX_THX · July 25, 2023, 7:29pm

Not that I know. I only copied and pasted the bone names and selected the same wheel class as the blue sedan from the dropdown menu.

Shunitzo · July 25, 2023, 7:31pm

Each skeletal meshes have there animations, so they need different animation blueprints.
You can change it above this

You need Anim Class

ZX_THX · July 25, 2023, 7:56pm

Great. That worked. Thanks! So basically you have to change everything. It would be maybe easier if there was a way to copy just the nodes from the Event Graph and the nodes from the Function from the sports car I set up to any new cars i want to use the follow spline set up with. Is this possible? I tried making and ctrl+c and ctrl+v and this didn’t work.

Shunitzo · July 25, 2023, 7:58pm

You can. You just need to adapt code to the new blueprint.