Question by D_Vainn · Jun 03 at 12:11 PM · 2d ai shooting math aim

AI reflect shooting

Hello there! I'm making a 2D action-platformer game with reflect shooting mechanics. The main problem is how to make AI predict bullet trajectory to catch a player. alt text

So is there any best way to find these blue sides of triangle? Well i had an idea to make a tons of Raycasts but i dont think this is the best way

reflectionexplanation.png (30.5 kB)

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Caeser_21 · Jun 03 at 12:53 PM 1

You can use Unity's built in method Vector3.Reflect() and Raycasts... I think this is the best way to do it

D_Vainn Caeser_21 · Jun 03 at 01:22 PM 0

There is no problem to reflect a vector. Bullets are reflecting. But the problem is how to find this direction. The only way i figured out is to cast thousands of raycasts and check all of them, but i dont think it's optimized enough

Caeser_21 D_Vainn · Jun 03 at 01:27 PM 0

Could you send a picture of your script too? Would be helpful in analyzing the issue and wat you are currently doing...

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elenzil · Jun 04 at 12:45 AM 2

will try to develop into a proper answer and a demo, but you can calculate the reflection point w/o too much trouble. as so often, similar triangles are your friends. alt text

img-8118.jpg (425.9 kB)

D_Vainn elenzil · 6 days ago 0

Well i got a genios solution on stackowerflow. The idea is to represent the reflecting ray as a mirrored space in one direction. alt text

Its sounds complicated but tt's actualy not. The only thing you need to do is to build a trajectory from a mirrored space to original character. If a ray from mirrored space goest to a player position without any collisions (exept outer walls) you can get the wall collision point to choose it's as a direction. If it's collides with inner walls - you can reflect it in a mirrored space, and if it's hit the mirrored player position - this also a right direction to shoot. So basicaly the only thing you need to do is to cast 3 rays from 3 mirrored spaces and check them. That all! Hope it's will help someone

For better understanding: center room is the original room

black and green rays is the expected direction to player position

right left and down rooms are mirrored spaces

blue dotted lines are mirrored caster directions to original player

green dotted lines are mirrored space reflected directions

scheme.png (40.2 kB)