# Collection proxies and physics

**URL:** <https://forum.defold.com/t/collection-proxies-and-physics/64252>\
**Category:** Questions\
**Created:** [January 9, 2020, 3:06pm UTC](https://forum.defold.com/t/collection-proxies-and-physics/64252 "2020-01-09T15:06:37Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![totebo](https://forum-defold.b-cdn.net/user_avatar/forum.defold.com/totebo/32/36087_2.png) [@totebo](https://forum.defold.com/u/totebo)\
**Post date:** [January 9, 2020, 3:06pm UTC](https://forum.defold.com/t/collection-proxies-and-physics/64252/1 "2020-01-09T15:06:37Z")

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I’ve been loading collection proxies in my GUI only game, which has been great to get the initial file size down.

Would I be able to do the same in a game using physics? Each collection comes with its own Box2D world, as I understand it, so would I be able to load multiple collections on demand and use their Game Objects with Collision Objects within the same physics world?

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**Author:** ![britzl](https://forum-defold.b-cdn.net/user_avatar/forum.defold.com/britzl/32/23_2.png) [@britzl](https://forum.defold.com/u/britzl)\
**Post date:** [January 9, 2020, 3:44pm UTC](https://forum.defold.com/t/collection-proxies-and-physics/64252/2 "2020-01-09T15:44:53Z")

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Game objects from one loaded collection proxy can’t interact with game objects from another proxy.

You can use collection factories with Load Dynamically checked to get similar benefits as with proxies.

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**Author:** ![totebo](https://forum-defold.b-cdn.net/user_avatar/forum.defold.com/totebo/32/36087_2.png) [@totebo](https://forum.defold.com/u/totebo)\
**Post date:** [January 9, 2020, 3:55pm UTC](https://forum.defold.com/t/collection-proxies-and-physics/64252/3 "2020-01-09T15:55:37Z")

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To keep the initial load down I use Live Update. Doesn’t Live Update need collection proxies for it to work?

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**Author:** ![britzl](https://forum-defold.b-cdn.net/user_avatar/forum.defold.com/britzl/32/23_2.png) [@britzl](https://forum.defold.com/u/britzl)\
**Post date:** [January 9, 2020, 5:22pm UTC](https://forum.defold.com/t/collection-proxies-and-physics/64252/4 "2020-01-09T17:22:02Z")

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> [@totebo](#):
>
> Doesn’t Live Update need collection proxies for it to work?

Yes that’s true.

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**Author:** ![totebo](https://forum-defold.b-cdn.net/user_avatar/forum.defold.com/totebo/32/36087_2.png) [@totebo](https://forum.defold.com/u/totebo)\
**Post date:** [January 9, 2020, 5:39pm UTC](https://forum.defold.com/t/collection-proxies-and-physics/64252/5 "2020-01-09T17:39:15Z")

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Alrighty, all good. I’ll have to think of a way to separate the heavy stuff (atlases) from the physics and load them separately.