Why the UE4 default ball is more round than my ball created in blender?

Development Asset Creation
1

I have created a simple ball in blender. It’s a UV Sphere. I have increased the number of Segments to 200 and the number of Rings to 100. I have applied Shade Smooth. This ball has much more polygons that the ball from the default UE rolling ball template. This is my ball created in blender :

Ball from Blender 2020-12-11 030322.png
Ball from Blender 2020-12-11 030322.png972×757 162 KB

And this is the ball from the UE rolling ball template :

Ball from UE Rolling Ball Template 2020-12-11 030404.png
Ball from UE Rolling Ball Template 2020-12-11 030404.png927×715 146 KB

However, the ball from UE4 is clearly more round that the ball I’ve created. It is obvious when I make each of them rolling.

My blender’s ball : [video]https://gyazo.com/d82b34db760bc7d9c019735552433cd9[/video]

The UE4 default ball : [video]https://gyazo.com/66225b5e6958195a438fc4f90b10183b[/video]

So what is the secret of the UE4 ball please !?? o_O

2

what’s the collision look like in engine?

3

The collisions look exactly the same :

The collisions in the Static Mesh look like this :

Capture d’écran 2020-12-11 193624.png
Capture d’écran 2020-12-11 193624.png485×802 39.8 KB

There is also the collisions of the BP, when I click on the Static Mesh Component called “Sphere”. In the two gifs I have posted above, I used the same BP. I just changed the Static Mesh in the apropriate pannel :

Capture d’écran 2020-12-11 194335.png
Capture d’écran 2020-12-11 194335.png545×826 40.8 KB

4

no, he talks about the shape of the collision geometry in the static mesh assets window. if you import youre ball, make sure to manually give it a “sphere collision” in the pull-down menu. then you should see a sphere collision geometry in the 3d window of the static mesh.

5

Oh, my bad ! I don’t know why I didn’t even look into this ! You are right. The engine autogenerated a collision shape that was pretty rough with sharp faces. So I removed it and just gone in the collision tab in the toolbar up above, and I clicked on “Add Sphere Simplified Collision” :

Capture d’écran 2020-12-13 212316.png](filedata/fetch?id=1842825&d=1607891021)

I also need to do the same but for a egg-shapped mesh. Is there a way to generate an oval box collision directly in UE4 ? Or should I create a custom collision box in my 3D app ? I didn’t find how this in UE4 so I created an UCX in Blender then UE4 has automatically detected it and now I have my oval box collision. Pretty cool but I had to increase significantly the number of faces with a subdivision surface modifier to have a really smooth collision. I note that the Sphere Simplified Collision has no face at all. It seems, at least. So is there a way to do the same thing but with an oval shape ?

EDIT : Well, there is the “Capsule Simplified Collision” for an oval shape. But I was thinking more about an egg shape, thicker at the bottom and thiner at the top. Maybe we can take the Capsule then edit it somewhere… But I don’t see where so maybe we can’t…

6

Inside the 3d program, copy the oval.
Simplify it a bit- doesn’t need 2000 poli.
Somerthing 'round 32 points per loop will probably be more than plenty.
Name the object UCX_objectname_0 and export.

Import in engine with the generate collision option disabled.
that should take care of it.

Take care of making sure that object names match exactly. Any preceding/post need to be included, like for instance _LOD0.

7

So that means I can’t do this directly in UE4, I presume. Ok, not a problem ! Blender works like a charm to do this ! The simplify modifier is awesome ! Thanks for the tip !