Touched not firing at the right moment

[Dfzoz]

I am trying to make a weapon that fires balls that has special properties (some bounce twice before expoding, some slide for 5 seconds after collision, some just explode on impact).
The problem is the server detects collision but at the wrong timing. My code is something like this:
bullet = bullet that was shot with velocity property change
bullet.Touched:Wait()
local bulletPosWhenTouched = bullet.Position

I tested this and it seems that the bulletPosWhenTouched is actually being registered as a position prior to the collision most times. Funny how the same code on localscript seems to work. I tried to correct it with raycasting but that way the gravity isn’t accounted on the last seconds, also giving unprecise results.

Edit: I need the exact position of the bullet at the time of collision, not the part that it touched, so I make an explosion at the right position. If my bullet hit the terrain and i get the terrain position it would return the middle of the terrain, which isn’t near the place that the explosion happened most times.

Does anyone know a way to fix this?

[ExcessEnergy]

Unfortunately the .Touched event isn’t too accurate when used on the Server.

The two solutions I can come up with is to either:

A. Calculate the hit position on client, by incorporating .Touched in a LocalScript. You will also have to set the Network Owner of the projectile to the player who created it.

Projectile:SetNetworkOwner(player)

B. Use Raycasting to detect the hit point instead of relying solely on .Touched timing.

Here is a post I found that seems to be concerning the same topic:

Touched event firing too early?

Hello there, I am having an issue where my projectiles kinda seem like they are firing their touched event too early. So I have projectiles flying from around 400 studs (Y-Axis Specifically) to 0-10 studs, this is done with the roblox physics engine with the part being un-anchored. I made it so that when the projectile hits the baseplate part called (“SpecificPart”) it prints outs its position. The issue I am having with this is that although the environment ranges from 0-10 studs on the Y Axis,…

[Dfzoz]

Yeah, I tried making a raycast from oldPosition and actualPosition, which updates every Stepped:Wait() (oldPosition = actualPosition then actualPosition=bullet.Position).
When the touch happens a ray is created with origin=oldPosition and direction = actualPosition, checking a collision and setting the actual position it collided. But physics isn’t applied on rays so sometimes when a ball hit the border of a slope the ray doesn’t hit that slope.

[ExcessEnergy]

In this case, since it seems that your map has some complex elements, I would recommend option A. Make sure to check out the post I linked, as the issue and solution was explained nicely.

[Dfzoz]

I think maybe i’ll add a testemony system. The damage is shown just for effect, but every player returns their end positions and the server compares them to see what the most probable result is. It’s a turn based game, so I don’t think it affects the gameplay that much, but it does gets a .2 second delay from knockback and damage being applied. I’ll try your Option A first though.

Edit: apply your option A and use testemony system working just to check hackers, not actually affecting gameplay, but more like an anticheat.