# Collision clings to a flat surface

**URL:** <https://forums.unrealengine.com/t/collision-clings-to-a-flat-surface/404693>\
**Category:** World Creation\
**Tags:** friction, unreal-engine, Physics, Collision, question\
**Created:** [September 15, 2017, 9:46pm UTC](https://forums.unrealengine.com/t/collision-clings-to-a-flat-surface/404693 "2017-09-15T21:46:55Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![anonymous\_user\_5faef967](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_5faef967](https://forums.unrealengine.com/u/anonymous_user_5faef967)\
**Post date:** [September 15, 2017, 9:46pm UTC](https://forums.unrealengine.com/t/collision-clings-to-a-flat-surface/404693/1 "2017-09-15T21:46:55Z")

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Hi! I have a question about phys material setup. I created an actor blueprint with static meshes (a car with wheels), created flat landscape and applied to them phys materials with same parameters:

 ![213651-1.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/b/a/6/ba65df2c451dd92ed0c19b690fb5ac7c93fdb739.png)

Also I turned on substepping and substepping async in project settings. Then I applied force on the Y axis to my car. At high speed values (about 100 km/h) my car flips over as if clinging to the flat surface.

 ![213652-3.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/1/c/b/1cba13fb542fcbfafb6e62096896b38bc7452441.png)

I tried to change friction combine mode and changing that to multiply helped, but did not solve the problem completely.  
What settings of physics or material settings I need to change to prevent this?

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**Author:** ![anonymous\_user\_82461f5f](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_82461f5f](https://forums.unrealengine.com/u/anonymous_user_82461f5f)\
**Post date:** [December 24, 2017, 8:34am UTC](https://forums.unrealengine.com/t/collision-clings-to-a-flat-surface/404693/2 "2017-12-24T08:34:30Z")

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Did you get any solution about it? I am experiencing the same issue

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<div class="post-metadata">

**Author:** ![anonymous\_user\_5faef967](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_5faef967](https://forums.unrealengine.com/u/anonymous_user_5faef967)\
**Post date:** [December 29, 2017, 3:48pm UTC](https://forums.unrealengine.com/t/collision-clings-to-a-flat-surface/404693/3 "2017-12-29T15:48:34Z")

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I was reading this is a PhysX 3.3 bug and now there is no solution for this except for a complete replacement of the physical engine. But I found a way to reduce effect by decreasing min contact offset in physics tab of project settings to the minimum value

![225387-1.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/3/a/e3a2169f604ff208685a6149bbe5826a41c6d357.png)