Dynamically spawned physics objects with collision

[mkremins]

Hi! We're building a custom hubs-cloud client and we'd like to dynamically spawn physics objects that collide with the ground and with one another. We're currently spawning physics objects as follows:

const ent = document.createElement("a-entity");
ent.setAttribute("networked", "template:#spawnedObj-drawing");
ent.setAttribute("body-helper", {
  collisionFilterMask: -1,
  gravity: {x: 0, y: -9.8, z: 0}
});
APP.scene.appendChild(ent);

...using the following template:

<template id="spawnedObj-drawing">
  <a-entity class="spawnedObj" geometry="primitive:sphere"></a-entity>
</template>

...but these spawned objects fall through the environment and don't collide with one another, even though -1 is the constant specified for COLLISION_LAYERS.ALL in constants.js.

Are we missing something about how the collisionFilterMask parameter to the body-helper is supposed to work, or looking in the wrong place entirely? Do we need to somehow manually specify a collider shape/size for our spawned objects? Does the fact that the objects are networked interfere with the physics behavior somehow?

Thanks in advance!

[johnshaughnessy]

Do we need to somehow manually specify a collider shape/size for our spawned objects?

Yes, you will need body-helper and shape-helper along with probably several more things to get the objects to behave as intended. I don't have any documentation on the physics system to point you to. The best resource we have for this is guide: Creating New Networked Interactables

[mkremins]

Awesome, thanks! shape-helper was exactly the thing we were looking for.