Remote Mouse Mapping With Dual Monitors

Yes - your suspicion is right: Remote Mouse uses the Windows virtual desktop coordinates, not the bounds of a single monitor. That’s why SetAbsolute is landing in the wrong spot when you have:

• multiple monitors,
• different DPI scaling,
• and a monitor arranged to the left of the primary (negative X region).

The important part

Your current math assumes:

• camera 320x240
• target screen 2560x1440

But SetAbsolute is not targeting "the primary monitor." It’s targeting the entire desktop space, which may be something like:

• left monitor: -1920 to 0
• right monitor: 0 to 2560

So if you map directly to 0..2560, the cursor will be offset whenever the actual virtual desktop origin isn’t 0,0.

Recommended approach in ARC

There isn’t a built-in ARC command that directly returns Windows virtual desktop bounds/monitor rectangles from the Remote Mouse skill itself.

Best practice

Use JavaScript or Python in the Script skill and compute your own mapping based on the monitor you want to control, then send the coordinates to Remote Mouse.

If you only want to control one specific monitor, the cleanest solution is:

1. Define that monitor’s rectangle in virtual desktop coordinates
2. Map camera coordinates into that rectangle only
3. Send the result to SetAbsolute

Example: map camera to the right monitor only

If your external 2560x1440 display is the one on the right, and its top-left virtual desktop origin is (0, 0), then:

var camW = 320;
var camH = 240;

// target monitor bounds in VIRTUAL desktop coordinates
var monX = 0;
var monY = 0;
var monW = 2560;
var monH = 1440;

var x = Math.round((getVar("$CameraObjectX") / camW) * monW) + monX;
var y = Math.round((getVar("$CameraObjectY") / camH) * monH) + monY;

controlCommand("Remote Mouse", "SetAbsolute", x, y);

If the target monitor is on the left and begins at -1920, then:

var camW = 320;
var camH = 240;

// left monitor in virtual desktop coordinates
var monX = -1920;
var monY = 0;
var monW = 1920;
var monH = 1080;

var x = Math.round((getVar("$CameraObjectX") / camW) * monW) + monX;
var y = Math.round((getVar("$CameraObjectY") / camH) * monH) + monY;

controlCommand("Remote Mouse", "SetAbsolute", x, y);

DPI scaling note

Windows DPI scaling can make this look "wrong" even when the math is correct.

A few practical tips:

• If possible, set both displays to the same scaling percentage while testing.
• Make sure ARC is running in the same DPI context as Windows scaling expectations.
• If ARC appears visually offset versus the actual cursor position, the issue is often per-monitor DPI awareness, not ARC math.

That said, the Remote Mouse skill itself still works with desktop coordinates - the main thing is that you must map into the correct virtual desktop coordinate system.

Important correction to your current formula

This:

$mx = Round(($CameraObjectX / 320) * 2560)
$my = Round(($CameraObjectY / 240) * 1440)

is only valid if:

• the target area starts at (0,0)
• and the target is exactly one monitor of that size

It does not account for:

• a monitor offset
• a negative origin
• virtual desktop width/height
• DPI scaling differences

Better way to do this in ARC

If you want this to be robust, I’d recommend:

• use the Script skill with JavaScript
• create constants for:
  • target monitor X
  • target monitor Y
  • target monitor width/height
• optionally clamp the values so the cursor never leaves the monitor
• apply smoothing before sending SetAbsolute

Example with clamping:

var camW = 320;
var camH = 240;

var monX = 0;
var monY = 0;
var monW = 2560;
var monH = 1440;

var rawX = Math.round((getVar("$CameraObjectX") / camW) * monW) + monX;
var rawY = Math.round((getVar("$CameraObjectY") / camH) * monH) + monY;

var x = Math.max(monX, Math.min(monX + monW - 1, rawX));
var y = Math.max(monY, Math.min(monY + monH - 1, rawY));

controlCommand("Remote Mouse", "SetAbsolute", x, y);

What I’d like to know

What is your end goal here?

Are you trying to:

1. move the mouse only on the external monitor,
2. move it across both monitors as one desktop, or
3. use the cursor as part of a larger vision-based control system for Six?

If you want, I can help you build the correct JavaScript version for your exact monitor layout, including left-of-primary and DPI scaling behavior. Questions like this are often best handled with the ARC AI Assistant inside the Script editor too, since it can rewrite the mapping logic right in ARC:
https://synthiam.com/Products/AI-Assistant