RedM Camera Helper Utility

ViceFx TeamSep 1, 20242 min read443 views

The CameraHelper utility is a powerful tool for RedM game developers who need to interact with the game camera system. This utility provides a comprehensive set of functions for camera manipulation, coordinate conversion, and entity detection through raycasting.

Features

The utility includes several key functions that make camera-related operations more manageable:

Camera position and rotation tracking
Coordinate system conversions
Raycasting for entity detection
Mathematical utilities for camera calculations

Implementation

Here's the complete implementation of the CameraHelper utility:

Lua

CameraHelper = {
    GetPosition = function()
        return GetGameplayCamCoord()
    end,
    
    GetRotation = function(unk)
        return GetGameplayCamRot(unk)
    end,
    
    DegToRad = function (degs)
        return degs * 3.141592653589793 / 180 
    end,
    
    RotationToDirection = function(rotation)
        local z   = math.rad(rotation.z)
        local x   = math.rad(rotation.x)
        local num = math.abs(math.cos(x))
        return vector3(-math.sin(z) * num, math.cos(z) * num, math.sin(x))
    end,
    
    WorldToScreenRel = function(worldCoords)
        local check, x, y = GetScreenCoordFromWorldCoord(worldCoords.x, worldCoords.y, worldCoords.z)
        if not check then
            return false
        end
        screenCoordsx = (x - 0.5) * 2.0
        screenCoordsy = (y - 0.5) * 2.0
        return true, screenCoordsx, screenCoordsy
    end,
    
    ScreenToWorld = function(giveX, giveY)
        local camVec2, camVec21
        camRot     = CameraHelper.GetRotation(2) + vec3(0, 45.0, 0.0)
        camPos     = CameraHelper.GetPosition()
        direction  = CameraHelper.RotationToDirection(camRot)
        camVec3    = camRot + vec3(10.0, 0.0, 0.0)
        camVec31   = camRot + vec3(-10.0, 0.0, 0.0)
        camVec32   = camRot + vec3(0.0, 0.0, -10.0)
        direction1 = CameraHelper.RotationToDirection(camRot + vec3(0.0, 0.0, 10.0)) - CameraHelper.RotationToDirection(camVec32)
        direction2 = CameraHelper.RotationToDirection(camVec3) - CameraHelper.RotationToDirection(camVec31)
        local rad  = CameraHelper.DegToRad(camRot.y)
        camVec33   = (direction1 * math.cos(rad)) - (direction2 * math.sin(rad))
        camVec34   = (direction1 * math.sin(rad)) + (direction2 * math.cos(rad))
        local find, screenX, screenY = CameraHelper.WorldToScreenRel(((camPos + (direction * 10.0)) + camVec33) + camVec34)
        if not find then
            return camPos + (direction * 10.0)
        else
            camVec2 = vec2(screenX, screenY)
        end
        local find2, screenX2, screenY2 = CameraHelper.WorldToScreenRel(camPos + (direction * 10.0))
        if not find2 then
            return camPos + (direction * 10.0)
        else
            camVec21 = vec2(screenX2, screenY2)
        end
        if math.abs(camVec2.x - camVec21.x) < 0.001 or math.abs(camVec2.y - camVec21.y) < 0.001 then
            return camPos + (direction * 10.0)
        end
        local x = (giveX - camVec21.x) / (camVec2.x - camVec21.x)
        local y = (giveY - camVec21.y) / (camVec2.y - camVec21.y)
        return ((camPos + (direction * 10.0)) + (camVec33 * x) + (camVec34 * y))
    end,
    
    RaycastForEntity = function(screenCoord, ignoreEntity, maxDistance)
        local world   = CameraHelper.ScreenToWorld(screenCoord.x, screenCoord.y)
        local camVec3 = CameraHelper.GetPosition()
        local camVec4 = world - camVec3
        camVec4       = norm(camVec4)
        local ray = StartShapeTestRay(camVec3 + (camVec4 * 1.0), camVec3 + (camVec4 * maxDistance), -1, ignoreEntity)
        local _, _, _, _, entity = GetShapeTestResult(ray)
        return entity
    end
}

Function Documentation

Camera Position and Rotation

`GetPosition()`

Returns the current position of the gameplay camera as a vector3.

Lua

local cameraPosition = CameraHelper.GetPosition()

`GetRotation(unk)`

Returns the current rotation of the gameplay camera. The unk parameter is typically set to 2.

Lua

local cameraRotation = CameraHelper.GetRotation(2)

Coordinate Conversions

`WorldToScreenRel(worldCoords)`

Converts world coordinates to screen relative coordinates.

Lua

local success, screenX, screenY = CameraHelper.WorldToScreenRel(worldCoords)

`ScreenToWorld(giveX, giveY)`

Converts screen coordinates to world coordinates.

Lua

local worldCoords = CameraHelper.ScreenToWorld(0.5, 0.5)

Entity Detection

`RaycastForEntity(screenCoord, ignoreEntity, maxDistance)`

Performs a raycast from the screen position to detect entities.

Lua

local entity = CameraHelper.RaycastForEntity(
    vec2(0.5, 0.5), -- Screen position vector2
    PlayerPedId(),   -- Ignore self
    10.0            -- Max distance
)

Utility Functions

`DegToRad(degs)`

Converts degrees to radians.

Lua

local radians = CameraHelper.DegToRad(90)

`RotationToDirection(rotation)`

Converts a rotation vector to a direction vector.

Lua

local direction = CameraHelper.RotationToDirection(rotation)

Example Usage

Here's a practical example of using the CameraHelper to detect an entity in the middle of the screen:

Lua

local entity = CameraHelper.RaycastForEntity(
    vec2(0.5, 0.5), -- Screen position vector2
    PlayerPedId(),   -- Ignore self
    10.0            -- Max distance
)
print(entity) -- Prints the detected entity ID

Credits

Original implementation by kasuganosoras.

Conclusion

The CameraHelper utility provides a robust foundation for camera-related operations in RedM development. Whether you're working on a complex camera system or simply need to detect entities in the player's view, this utility offers the essential functions you need.

Snippet RedM