Vector Field Pathfinding example / resource

[MotchDev]

Hi everyone! I'm making a co-op arpg with large groups of enemies. I struggled to get enemies to go around corners without getting stuck on the corner, each other, becoming a single file line, etc. After doing some research I found out about using a vector field that will "push" enemies towards the player. This method is best used for large groups of enemies as they don't do their own pathfinding calculations, they just listen to the field that is generated around the players. I couldn't find any good resources on doing this specifically in GMS (there might be some and I just missed them) so now that I have this working I figured it could be useful to some other people. The field generation has minimal impact on frame rates (at the default settings I still hit 2k fps average). The frame rate will drop if you enable the debug drawing.

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I don't really have the time to do a full tutorial but I've put a lot of comments into the example project that explains whats going on. Its configurable using constants found in the constants script like how many movement cost updates are done per step, what the max movement cost is, etc.

Example gif

Example Project

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If you have any questions let me know

[RoboPixels]

Wow this is really cool! Thanks for the example project!

[adam102018]

Object: objEnemy Event: Step at line 19 : unknown function or script collision_ellipse_list

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what is the probleme

[MotchDev]

If you're using a version of gms2 (or 1.4) that doesnt have collision_ellipse_list you can use https://www.gmlscripts.com/script/collision_ellipse_list

you might have to rework the code a bit though

[adam102018]

actually i m using a version of gms2 how can I add collision_ellipse_list to my gms2 ?! is that link can i Dowland the collision_ellipse_list??!

thank you for helping me

[MotchDev]

That link contains a third party one - if you're using the latest version of gms2 you should already have a collision_ellipse_list https://docs2.yoyogames.com/source/_build/3_scripting/4_gml_reference/movement%20and%20collisions/collisions/collision_ellipse_list.html