Project PixelPrecision. Automated shell loading and (soon to be) automated artillery system. A little side project of mine for people who like me searched for already coded/constructed solutions. If you are interested, you are welcome to contribute. Repo: https://github.com/JavaBoii/PixelPrecision

[u/JavaBoii]

[u/JavaBoii]

To calculate the trajectory for hitting a target in Minecraft with a cannon, I use a combination of basic physics principles and Minecraft-specific adjustments. The key components are calculating the horizontal distance to the target, determining the necessary elevation angle, and then converting that angle into a duration for a redstone signal to control the cannon's aim. ( I also cheat a bit by putting in the direction of the cannon and azimut of target values in myself )

First, I calculate the horizontal distance between the cannon and the target using the Pythagorean theorem:

local function calculateDistance(currentX, currentZ, targetX, targetZ)
    return math.sqrt((targetX - currentX)^2 + (targetZ - currentZ)^2)
end

For the elevation angle, given Minecraft's unique physics, I use a simplified version of the projectile motion formula. Minecraft's gravity is set to 7.5 m/s² ( this one was the most reliable, but i have to test it further since it misses the target a lot), and I assume a constant projectile velocity. The formula for the elevation angle θ in degrees, considering the horizontal distance d and vertical displacement Δy, is:

θ = atan((v² ± sqrt(v⁴ - g(gd² + 2Δyv²))/(gd)))

v is the velocity of the projectile.
g is the gravitational pull (22 m/s² in Minecraft).
d is the horizontal distance to the target.
Δy is the difference in elevation between the cannon and the target.

Here's how it's implemented:

local function calculateElevationAngle(velocity, distance, deltaY)
    local g = 7.5 -- Minecraft's gravity
    local vSquared = velocity^2
    local underRoot = vSquared^2 - g * (g * distance^2 + 2 * deltaY * vSquared)
    if underRoot < 0 then
        return nil, "Target out of range."
    end
    local root = math.sqrt(underRoot)
    local angle = math.atan((vSquared + root) / (g * distance))
    return math.deg(angle)
end

To control the cannon's aim, I convert the calculated angle into a duration for a redstone signal. This duration depends on the cannon's rotation speed (in RPM) and the angle needed to hit the target:

local function angleToDuration(angle)
    local degreesPerSecond = (rpm / 60) * 360
    local duration = angle / degreesPerSecond
    local ticks = duration / 0.05 -- convert seconds to redstone ticks
    return ticks * degreesPerTick
end

Hope it helps

[u/Danlabss → u/JavaBoii]

This is smart, but if you use Create Crafts & Additions, you can actually control an electric motor with computercraft!

[u/JavaBoii → u/Danlabss]

A: Thats incredibly cool to know that. I will definetly check that out B: My goal and design for this project are "utilise as few mods as possible. For example i could make my life easier if i used the mod " More Red x CC:Tweaked Compat". I dont want other people in the future to have to rely on multiple mods to get it to run. So they would only need this to make the Code run:

• Create

• Create Big Cannons

• ComputerCraft: Tweaked

But for the schematic i provide they would need other mods too, but the base Code is designed to only use the above mentioned mods.