RopeImpostor with ExtrudeShape error

Bugs
1

I’m using the Ammo.js Physics Engine with a RopeImpostor, on an ExtrudeShape. The shape by default is given a cap of NO_CAP, but when I try to cap the ExtrudeShape with CAP_START, CAP_END, or CAP_ALL I get the following error.

TypeError: colShape.get_m_cfg is not a function. (In 'colShape.get_m_cfg()', 'colShape.get_m_cfg' is undefined)

src/sourceES6/core/Physics/Plugins/ammoJSPlugin.ts:418

  415 | var mass = impostor.getParam("mass");
  416 | impostor._pluginData.mass = mass;
  417 | if (impostor.soft) {
> 418 |     colShape.get_m_cfg().set_collisions(0x11);
^ 419 |     colShape.get_m_cfg().set_kDP(impostor.getParam("damping"));
  420 |     this.bjsAMMO.castObject(colShape, this.bjsAMMO.btCollisionObject).getCollisionShape().setMargin(impostor.getParam("margin"));
  421 |     colShape.setActivationState(AmmoJSPlugin.DISABLE_DEACTIVATION_FLAG);

The documentation says only “path” and “shape” are supported, but I would expect that instead of throwing an error, that the cap parameter would always be set to 0 (regardless of how the user sets the value).

Ideally, I’d like to use RopeImpostor with a capped extrude, even if the caps were ignored by the imposter.

1 Like
2

I have been fiddling for a time with ‘the Rope’:wink: I’m still not sure of how much ‘the Rope’ is really useable as a Rope. But I found it nice to simply use as an impostor because of its properties. But the visual aspect and also physics behavior of ‘Rope’ did not entirely convince me. And I don’t think there’s a way to add caps, except for creating an anchor both ends and attaching a cap shape to it. I didn’t want to try this since it sounds a bit odd… I coped without the caps for just my purpose (of simply attaching two ropes to a flag).

3

Adding @Cedric and @RaananW our Physics Masters to double check :slight_smile:

5

@mawa can you provide a PG for your use case?
It seems Config has been exposed differently in ammojs

And we didn’t update the plugin.

6

Totally possible following the upgrade last time. Would be great if you can have a look @Cedric :frowning:

7

I put that on my todo list

1 Like
8

Hi,
what do you mean with ‘*my case’? As I said, I did without the caps.
I only found it hard to have my rope behave correctly with my hooks and anchors (and mass, collision with my soft body flag… I was actually just implementing ‘the rope’ the night before the update was done (bloody me, I always kick in where I shouldn’t :wink:

1 Like
9

PR is live: [physics]Removed irrelevant check on shape extrusion by CedricGuillemet · Pull Request #9829 · BabylonJS/Babylon.js · GitHub

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