Screenshotter

Combined with a small Node.js server, roblox-screenshot takes, crops, and masks screenshots of the Roblox viewport for automated screenshotting.

For docs, see module.lua.

For examples, see ExamplePatterns.lua and Tests.lua.

You can use the module in Studio at any time with

local Screenshotter = require(2218503664)

Installation

Head to the Releases page to download the latest release. Unzip it and place it somewhere you can run it from.

Head to the Node.js page and download the Current version. Install Node.js. Make sure that you install npm and that node and npm are added to your PATH.

Windows:

1. Run Install.bat, which downloads all of the dependencies

Mac:

1. Open the terminal to the roblox-screenshot folder
2. Run npm install
3. Turn off allow_previews and allow_registry_login in settings.json

Running

Check settings.json to make sure the settings are to your liking.

• allow_previews allows scripts to copy screenshots to your Roblox content directory to preview screenshots in-game.
• allow_uploads allows scripts to upload screenshots to Roblox
• allow_registry_login allows scripts to upload screenshots to your account. Scripts do not see your login cookie.
• allow_password_login allows scripts to upload screenshots to accounts that they have the username and password for. Scripts do see these login cookies.

Windows:

1. Run Run.bat

Mac:

1. Open the terminal to the roblox-screenshot folder
2. Run node .

While calibrating or taking screenshots, you must leave the Roblox Studio window open and leave it unobstructed. roblox-screenshot takes a screenshot of your screen and crops it down to the Roblox Studio viewport, so roblox-screenshot will only work properly if Roblox Studio is on top.

Compatibility

The server should work on Mac (and Linux). I have no way to test this out though, and the following restrictions apply to the Mac server if it works:

• Previews will not work, as I don't know where the Roblox directory is on Mac. You should turn previews off in settings.json to avoid errors.
• Registry login will not work, since the Registry is a Windows feature.

Advice or pull requests to fix these features or to fix general Mac compatibility is appreciated and encouraged.

Issues

Display scaling on Windows

Display scaling on windows can cause the screenshot program to not take screenshots of the whole screen. Install.bat will automatically add registry keys to disable scaling for the screenshot program. If this does not work for you, you will need to go to node_modules/screenshot_desktop/lib/win32 and change the compatibility options of screenCapture.exe yourself. You will need to run Calibrate or Screenshot from the Lua module at least once for this file to appear.

Package issues

Some packages are included using their github address instead of automatically through npm.

• screenshot-desktop does this because it uses some changes I made to add png support.
• tough-cookie and winreg do this because I was having issues with their npm packages, but the versions on github do not have the issues.

HTTP API doesn't do validation

Since roblox-screenshot is meant to be used from the Lua module, the Lua module does all of the validation. The Node HTTP API doesn't do any validation and will just error if used incorrectly. The main exception to this is that file names are sanitized, so it's not possible to create or delete files outside of screenshots and previews using roblox-screenshot.

roblox-screenshot does not check what is using it

Any program on the computer can use roblox-screenshot to take screenshots, and roblox-screenshot might be open to other computer on the local network or the internet if you have a public IP and no firewall. This is not a major issue because:

• Any program that can use roblox-screenshot to take screenshots could do so itself. Any program that can use roblox-screenshot to make many files/folders for malicious purposes could do so itself much faster than it could by using roblox-screenshot.
• It's highly unlikely for anyone to target roblox-screenshot from other computer.
• roblox-screenshot does not release any useful information in its API results. It does not serve up images of screenshots, it does not allow modifying files outside of its screenshots or previews directories, and it does not allow writing or reading arbitrary data.

These issues can be solved with some sort of key authentication where the user has to grant programs and processes the ability to use roblox-screenshot. This is a nice long-term goal, and will fit best if roblox-screenshot ever has a better user-facing UI using something like Electron.

As it is, the risks are not great enough to focus significant time on this.

TODO

• Utility API for creating pseudo-particles that stay static between masked screenshots
• Find a background object that is unaffected by fog
• API to get existing spritesheet info saved in json files
• API to get directory contents
• Support directory arguments in Preview and Unpreview endpoints
• Add key authentication