A Starfall-based SetAng steering chip with decent counter-steering abilities

Car Steering v3.4.lua

--@name Car Steering v3.4
--@author Cheezus
--@shared
--@model models/sprops/rectangles_thin/size_2/rect_12x12x1_5.mdl

local showAxes = true

local frontWheelPos = Vector(50, 0, 0) -- Between your front wheels
local rightAxis     = Vector(0, -1, 0) -- The RIGHT facing direction of your car
local upAxis        = Vector(0, 0, 1) -- The UP facing direction of your car
local fwdAxis       = rightAxis:cross(-upAxis)

rightAxis:normalize()
upAxis:normalize()

if SERVER then
    local maxAngle = 45 -- Maximum steering angle, in degrees
    local steeringForce = 120 -- Maximum steering force, affects steering rate and how much your inputs overpower the countersteer
    local casterAngle = 0 -- Caster angle, in degrees

    local slipCounterForce = 1 -- Stops you from slipping sideways
    local gyroCounterForce = 1 -- Stops you from rotating, tries to maintain current angle

    local counterMax = 180 -- Maximum counter force, can be completely overpowered by manual inputs if lower than steeringForce

    local antiWobbleAngle = 1.5 -- Lower than this angle, multiply the current steering angle by the value below every tick
    local antiWobbleMul = 0.25 -- This helps cars that have a tendency to wobble while driving straight at high speeds

    local addRateMul = 0 -- Increases manual steering power based on velocity, 0 to disable, increase in increments of 1-2

    local interval = 2 -- Run every X ticks

    wire.adjustPorts({
        Base = "entity",
        A = "number",
        D = "number",
        Active = "number"
    }, {
        SteeringAngle = "number",
        Slip = "number",
        VelL = "vector",
        Understeer = "number",
        Oversteer = "number"
    })

    local clamp = math.clamp
    local abs = math.abs
    local chip = chip()
    local dt = game.getTickInterval() * interval

    net.receive("requestBase", function(_, ply)
        if not wire.ports.Base:isValid() then return end

        net.start("sendBase")
        net.writeEntity(wire.ports.Base)
        net.send(ply)
    end)

    chip:setCollisionGroup(COLLISION_GROUP.WORLD)

    local steeringAngle = 0

    local tickCount = 0
    hook.add("tick", "interval", function()
        local active = wire.ports.Active > 0

        tickCount = tickCount + 1

        if tickCount % (active and interval or 10) ~= 0 then
            return
        else
            tickCount = 0
        end

        local base = wire.ports.Base
        if not base:isValid() then return end

        local localUpAxis = base:localToWorldVector(upAxis)

        if active then
            local a = wire.ports.A
            local d = wire.ports.D

            local fwpos = base:localToWorld(frontWheelPos)
            local velL = base:worldToLocal(base:getPhysicsObject():getVelocityAtPoint(fwpos) + base:getPos()) * dt
            local slip = velL:rotateAroundAxis(localUpAxis, -steeringAngle):dot(rightAxis)

            wire.ports.Understeer = slip / velL:getLength()
            wire.ports.Slip = slip
            wire.ports.VelL = velL
            slip = slip * slipCounterForce

            local rearPos = -frontWheelPos * -upAxis
            local rearVel = base:worldToLocal(base:getPhysicsObject():getVelocityAtPoint(rearPos) + base:getPos())
            wire.ports.Oversteer = rearVel:dot(rightAxis) / rearVel:getLength()

            local yawDamping = base:getAngleVelocity():dot(localUpAxis) * dt
            --yawDamping = yawDamping * upAxis.z
            yawDamping = yawDamping * gyroCounterForce

            local addRate = velL:getLength() * addRateMul

            local turn = (a - d) * (steeringForce + addRate) * dt
            local counter = clamp(slip + yawDamping, -counterMax, counterMax)

            steeringAngle = clamp(steeringAngle + turn - counter, -maxAngle, maxAngle)

            if (abs(steeringAngle) < antiWobbleAngle) and (a == 0 and d == 0) then
                 steeringAngle = steeringAngle * antiWobbleMul
            end
        else
            steeringAngle = 0
        end

        local casterAxis = base:localToWorldVector(fwdAxis):rotateAroundAxis(localUpAxis, steeringAngle)
        local casterRotation = steeringAngle / maxAngle * casterAngle
        local finalAngle = base:getAngles():rotateAroundAxis(localUpAxis, steeringAngle):rotateAroundAxis(casterAxis, -casterRotation)
        chip:setAngles(finalAngle)

        wire.ports.SteeringAngle = steeringAngle
    end)

    timer.create("freezer", 0.5, 0, function()
        if not chip:isPlayerHolding() and not chip:isFrozen() then
            chip:setFrozen(true)
        end
    end)
elseif player() == owner() then
    if not showAxes then return end

    local base

    timer.create("requestBase", 0.5, 0, function()
        net.start("requestBase")
        net.send()
    end)

    net.receive("sendBase", function()
        base = net.readEntity()

        timer.stop("requestBase")
    end)

    enableHud(owner(), true)

    local font = render.createFont("Trebuchet24", 24, nil, false, nil, nil, true)

    hook.add("drawHud", "hud", function()
        if not base or not base:isValid() then return end

        local basePos = base:localToWorld(frontWheelPos)
        local right = base:localToWorld(frontWheelPos + rightAxis * 50)
        local up = base:localToWorld(frontWheelPos + upAxis * 50)
        local fwd = base:localToWorld(frontWheelPos + fwdAxis * 50)
        local alpha = math.max(300 - owner():getPos():getDistanceSqr(basePos) / 1000, 0)

        if alpha > 0 then
            render.pushViewMatrix({
                type = "3D"
            })

            render.setColor(Color(255, 0, 0))
            render.draw3DLine(basePos, right)

            render.setColor(Color(0, 255, 0))
            render.draw3DLine(basePos, up)

            render.setColor(Color(0, 0, 255))
            render.draw3DLine(basePos, fwd)

            render.popViewMatrix()

            local rightScr = right:toScreen()
            local upScr = up:toScreen()
            local fwdScr = fwd:toScreen()

            render.setFont(font)

            render.setColor(Color(255, 0, 0, alpha))
            render.drawSimpleText(rightScr.x, rightScr.y, "Right", 1, 1)

            render.setColor(Color(0, 255, 0, alpha))
            render.drawSimpleText(upScr.x, upScr.y, "Up", 1, 1)

            render.setColor(Color(0, 0, 255, alpha))
            render.drawSimpleText(fwdScr.x, fwdScr.y, "Forward", 1, 1)
        end
    end)
end