How to Use a Digital TableTop with an Infrared (IR) Touchscreen
The setup
The GM has a laptop at the table, with their display extended to a TV that is laying flat plugged in via HDMI. Maps are shown on the TV to the players around the table. Optionally, an IR touch device is plugged in to the GM's laptop via USB.
Selecting a Virtual Tabletop (VTT)
If you are not using a touchscreen, there are a variety of options. My recommendation of course is my own Digital TableTops VTT on Steam (link). It is designed specifically for in-person sessions. It is lightweight (runs well on older hardware), easy to use, and 100% free.
The most well-established commercial VTT made specifically for in-person sessions is Arkenforge (link). It is a one-time fee of $35, no subscription required. It has a steeper learning curve but if you are in need of more features, it is a great choice.
You can use nearly any browser based VTT with this type of setup. Roll20 (link) and Owlbear Rodeo (link) are popular choices. Both are easy to use and offer free tiers but require a subscription for advanced features.
Simply have the GM sign in on one browser window and have another browser log in as a player (preferably a different browser or at least a window in incognito mode). Make this second browser full-screen to be displayed on the TV.
Foundry VTT (link) is probably the most powerful VTT available. The core program runs in its own window, and any number of users can log in via a browser. It is a one-time fee of $50 and has a steeper learning curve than the previously listed options.
Part of what makes Foundry so powerful is its robust system of community contributed modules. I released a free module that will help display maps for in-person play. Simply install it as you would any other module (manifest URL link).
Using an IR Touchscreen
Large format IR touch frames are readily available and relatively affordable compared to capacitive touch devices this size. When a finger (or mini) is placed in its field, the touch device sends the coordinates to the operating system. Here's where things get tricky.
If you have a mini resting on the TV, the IR device will constantly be sending those coordinates to the OS, which will constantly attempt to move the mouse cursor to that location. This is a problem, and renders the laptop useless for any other function. In other words, you cannot use the same laptop to GM as you use for detecting touches.
The usual solution is to have the touch device connected to an entirely separate computer dedicated just to touch input. Similar to the browser based VTT setup described previously.
It took years of effort, but I finally figured out a way to prevent the IR device from sending touch data to the OS. My custom software intercepts the data and sends it to your VTT of choice directly. It's built in to my own VTT, but I also released lightweight clients that work with Arkenforge and Foundry on GitHub (link).
Using my software, when you move a physical mini in the real world their respective digital token moves instantly like magic! Touches do not cause the mouse cursor to move, allowing you to use the laptop for GM stuff as well.
The software does not require any special configuration. Simply load up your VTT and run the client (the order you open things shouldn't matter). If you're using my own VTT, then you don't even need to do that: it's all handled by the VTT already.
For Foundry, make sure the browser for the TV is logged in as a player named "TV" and that the player has ownership of tokens you want the touchscreen to be able to control.
The One Caveat
There is one potential hiccup: my touch software is only compatible with certain IR devices, not every single device on the market. I've tested it with various IR frame models from:
- Greentouch
- SpecialTouch
- TouchSmith
- TouchWo
- YCLTouch
Please keep in mind that I cannot guarantee ANY IR touch device is compatible other than the ones I sell here.
Nearly all modern, consumer level touch frames use very similar firmware and configuration tools. Hence the wide range of compatible models. My software will tell you instantly whether your IR touch frame is compatible. It will also detect if it might be compatible with instructions on how to contact me to get it added.
For most IR touch devices, if their beam is blocked for too long (such as when a mini is stationary for more than a few minutes) it turns off those sensors as it assumes they are damaged. This causes touches in that area to be misdetected. A real problem for TTRPG use.
Since I purchase so many, the manufacturer has made me custom firmware that does a neat trick: it turns off this timeout/inactivity timer. You can have your minis rest for hours and come back and everything still works as when you first plugged it in.
So if you don't already own an IR touch frame, you really are better off getting one from me. It will work better on its own, is sure to be compatible with the special software to enable use on a single PC, and you'll be helping to fund development of said software.