# Check polygon overlay inside processCallback

**URL:** <https://phaser.discourse.group/t/check-polygon-overlay-inside-processcallback/8042>\
**Category:** Phaser 3\
**Created:** [November 6, 2020, 11:24am UTC](https://phaser.discourse.group/t/check-polygon-overlay-inside-processcallback/8042 "2020-11-06T11:24:04Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dinoq](https://yyz2.discourse-cdn.com/free1/user_avatar/phaser.discourse.group/dinoq/32/4313_2.png) [@dinoq](https://phaser.discourse.group/u/dinoq)\
**Post date:** [November 6, 2020, 11:24am UTC](https://phaser.discourse.group/t/check-polygon-overlay-inside-processcallback/8042/1 "2020-11-06T11:24:04Z")

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Hello, is there way in arcade physics to check intersection/overlay of two polygon (Phaser.Geom.Polygon)? Probably there is way to calculate it mannualy, but I thing if there is already any function in Phaser for that purpose?  
What I have found is only Phaser.Geom.Intersect class, but it have no function to check interect of two polygons (only rectangles, triangles and so on…)

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**Author:** ![Telinc1](https://yyz2.discourse-cdn.com/free1/user_avatar/phaser.discourse.group/telinc1/32/60_2.png) [@Telinc1](https://phaser.discourse.group/u/Telinc1)\
**Post date:** [November 6, 2020, 1:29pm UTC](https://phaser.discourse.group/t/check-polygon-overlay-inside-processcallback/8042/2 "2020-11-06T13:29:18Z")

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Polygon intersection is not straight-forward, so Phaser doesn’t offer anything built-in. Check out an external library like [SAT.js](https://github.com/jriecken/sat-js).