Change shape of physics aggregate (havok)

Questions
1

Hello,
I’m trying to change the shape of a physics body on the press of a button.
I’m using a physics aggregate to create the initial, shape, body etc.
I’ve read through this thread which has some additional details.
However, setting the aggregate’s shape to a newly created one seems to do nothing for me.
See this PG: https://playground.babylonjs.com/#4Y813L#38
I didn’t want to pollute the mentioned thread with this question, so I’m posting a new one.
Is there a way to get the shape to change dynamically?

2

cc @Cedric

3

See the bottom of this post:

4

Hi HiGreg,

I read your post (linked in the thread about scaling the shape), but it’s not working if I use an aggregate (see the PG). Am I missing something?
Setting the shape of the body again doesn’t seem to do anything in this case…

5

Try convert your code to using PhysicsBody and PhysicsShape instead (as detailed in that link). I had difficulty changing shape.density within the PhysicsAggregate. It might not be the same problem as yours, but PhysicsAggregate is just a convenience function for those moving from PhysicsImposter. I ran into one limitation, so I’d expect there to be others.

6

Yes that’s probably the best thing to do, I’ll get to converting my code tomorrow and see if it works.

7

I’m curious now :slight_smile: Do you have a repro PG? It should be exactly the same between aggregate and body/shape usages.

8

I don’t think I have a repro.

I’m guessing the problem is in physicsAggregate.ts on line 165:

this.body.setMassProperties({ mass: this._options.mass });

Because the body’s user physics property mass is set by the aggregate, it always overrides the calculated (internal) one from the shape.

That’s my guess.