# Integrated PhysX collision issue

**URL:** <https://forums.unrealengine.com/t/integrated-physx-collision-issue/341216>\
**Category:** World Creation\
**Tags:** integration, physx, unreal-engine, Collision, question\
**Created:** [December 12, 2015, 2:14am UTC](https://forums.unrealengine.com/t/integrated-physx-collision-issue/341216 "2015-12-12T02:14:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![DivideByZero](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@DivideByZero](https://forums.unrealengine.com/u/DivideByZero)\
**Post date:** [December 12, 2015, 2:14am UTC](https://forums.unrealengine.com/t/integrated-physx-collision-issue/341216/1 "2015-12-12T02:14:49Z")

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I was trying to use PhysX directly as described [here](https://wiki.unrealengine.com/PhysX,_Integrating_PhysX_Code_into_Your_Project).It looks like PhysX uses cm units like Unreal. I have a ground plane and cube I created in UE4 and a sphere I created directly in PhysX. The sphere and cube fall at the same rate but only the cube collides with the ground. I’m guessing I need to set some flags/settings on the sphere shape.

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<div class="post-metadata">

**Author:** ![DivideByZero](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@DivideByZero](https://forums.unrealengine.com/u/DivideByZero)\
**Post date:** [December 12, 2015, 4:16am UTC](https://forums.unrealengine.com/t/integrated-physx-collision-issue/341216/2 "2015-12-12T04:16:15Z")

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Looks like it works if I use

```
physx::PxFilterData collFilterData;
collFilterData.word0 = 1;
collFilterData.word1 = 1;
shape->setSimulationFilterData(collFilterData);

```

But I might try and use CreateShapeFilterData() instead.