Common problems and how to fix them with settings, camera position, or tray setup. Use the links below to jump to your issue, or scroll through for a full list.

Camera not showing or wrong camera selected

If RollSight doesn't show a camera feed, or shows the wrong camera (e.g. laptop webcam instead of your dice camera):

Select the correct camera: In Settings → Camera, choose your dice camera from the dropdown. Names are often generic (e.g. "USB Video Device") — unplug others to identify which is which, or use the Camera calibration wizard to pick from a list.
Camera in use elsewhere: Close other apps that might be using the camera (Zoom, OBS, another browser tab, system camera app). Only one app can use the camera at a time on most systems.
Permissions: On macOS, grant RollSight camera access in System Settings → Privacy & Security → Camera. On Windows, check Settings → Privacy → Camera. Restart RollSight after granting access.
Driver or USB: Try a different USB port (preferably directly on the computer, not through a hub). If the camera never appears in RollSight or in the system at all, reinstall the camera driver or try another cable. See USB and hardware tips below.

Camera feed black, frozen, or disconnecting

The camera opens but the image is black, freezes after a few seconds, or drops out during use.

Black screen: The camera may need a moment to start — wait 5–10 seconds. If it stays black, another app may have the camera; close Zoom, OBS, browser video, etc. On some USB cameras, unplug and replug, then restart RollSight. Check that the lens cap is off and the camera isn't covered.
Frozen feed: Often caused by USB bandwidth or driver issues. Close other USB devices (external drives, hubs) or use a different USB port. Restart RollSight. If it freezes only when you do something specific (e.g. open Settings), try avoiding that action and report it — it may be a bug.
Disconnects mid-session: Loose cable, power-saving (USB or camera going to sleep), or a flaky USB port. Secure the cable, plug into a different port, and disable USB selective suspend in Windows power options if on PC. On some document cameras, keep the device powered and avoid long idle periods.

Dice not being detected

If RollSight isn't finding your dice, work through these in order. Most issues come from lighting, the capture region, or the tray surface.

1. Check the capture area

The tray region (polygon mask) defines where RollSight looks for dice. If your dice land outside that region, they won't be detected.

Go to Settings → Camera (or the Camera calibration wizard).
Use Set tray region / Tray region and draw a polygon that fully covers where your dice actually land.
If you never set a region, the whole frame is used—but if the camera sees a lot of desk or background, try defining a tighter region so only the tray is inside it.
If you have a tray region set and moved the tray or camera, the polygon may no longer match — re-draw it. See Tray or camera moved.

2. Lighting (too dark or too bright)

Low light is a very common cause. Bright, even light on the tray helps.

Too dark: Enable Lighting boost in Settings (Camera/Display). Increase the level (25 → 50 → 75 → 100) until the feed looks clear. Add a small lamp or ring light aimed at the tray if the room is dim.
Too bright / washed out: Run Calibrate Background (Settings → Camera) with the tray empty and well lit. That adjusts brightness and contrast for your setup. Reduce room or lamp intensity if the image is blown out.

3. Focus (blurry image)

If the camera feed is blurry, dice won't be read reliably.

In the Camera menu, use Calibrate Focus if your camera supports it (many USB document cameras and webcams do).
Position the camera so the tray is at the right distance for the lens (not too close, not too far).
Ensure the camera is stable; movement can cause blur.

4. Tray surface

RollSight is trained and tuned for dark backgrounds. Light or brightly colored trays can cause missed dice or false detections.

Use a black or dark tray. Lining a light tray with black self-adhesive felt (cut to size) often fixes recognition. See the webcam guide for a suggested product.
Avoid reflective or glossy surfaces that create hotspots or glare.

5. Dice contrast and type

Clear or translucent dice are harder to read. Dice that match the tray color (e.g. dark on black) are also tougher.

Opaque dice with good contrast against the tray work best.
Custom or unusual dice can be trained in RollSight so the model learns your specific set.
Very small dice (tiny d6, small d4) may need the camera closer or a higher resolution; see Small dice, overlapping dice.

6. Background calibration

Calibration tells RollSight what your empty tray looks like so it can separate dice from the background.

Go to Settings → Camera and run Calibrate Background.
Place the tray in view with no dice, then click Capture & Calibrate. Do this under the same lighting you use when rolling.
If you changed lighting or moved the tray, run calibration again.

7. Detection confidence

In Settings you can adjust how strict the detector is.

Dice missed: Try lowering the detection confidence so smaller or less obvious dice are still picked up.
Tray or felt detected as dice: Raise the detection confidence so only clear dice shapes are counted (see False detections).

False detections (tray or background counted as dice)

RollSight is detecting something that isn't a die — e.g. a fold in the felt, a shadow, or a pattern on the tray — and showing it as an extra die or wrong count.

Raise detection confidence: In Settings, increase the detection confidence threshold. That makes the detector pick only high-confidence dice and ignore ambiguous shapes.
Tighten the tray region: Use Set tray region so only the actual rolling area is inside the polygon. Exclude desk edges, cables, or textured areas that might look like dice.
Improve tray surface: Use a flat, uniform dark surface. Wrinkles in felt, seams, or busy patterns can trigger false detections. Smooth the felt or use a solid dark tray.
Re-run background calibration: With the tray empty and under your normal lighting, run Calibrate Background again. That helps RollSight learn what "background" looks like so it doesn't confuse it with dice.

Wrong value read / misreads

RollSight detects dice but reads the wrong face (e.g. 5 instead of 2). Common causes and fixes:

Glare or reflection: Move lights so they don't create a hotspot on the dice. Matte dice tend to read better than glossy ones. Avoid direct light bouncing off the dice surface.
Dirty or dusty lens: Gently clean the camera lens. Smudges can distort the image and cause misreads.
Angle: The camera should look as straight down at the tray as possible (close to 90°). Severe angles can make pips or numbers hard to interpret.
Custom or unusual dice: If you have non-standard pips, symbols, or fonts, use RollSight's training so the model learns your dice. After training, recognition for those dice should improve.
Re-run background calibration: Do it under the same lighting you use when rolling, with the tray empty. Lighting drift (e.g. time of day) can affect contrast and cause misreads.
Dice still moving: If RollSight is reading before the dice settle, you may get wrong values. See Dice read too early or while still moving.

Wrong die type (d6 vs d20, etc.)

RollSight detects the value correctly but labels the die as the wrong type — e.g. a d20 read as a d6, or vice versa.

Shape and size: The model infers die type from shape and size in the image. Very small d20s or large d6s can sometimes be confused. Training with your specific dice can help.
VTT roll type: When sending to Foundry (or other VTT), the roll type (e.g. "d20", "2d6") is determined by what RollSight detects. If the mix of dice on the tray doesn't match what you intended (e.g. you rolled one d20 but two are detected), remove extra dice from the tray or use Rescan after placing only the dice you want to send.
Training: If you use non-standard dice (e.g. rounded d20s, unusual d4s), training them in RollSight can improve both value and type recognition.

Focusing the prediction area on a hexagonal (or odd-shaped) tray

RollSight can limit detection to a custom region that matches your tray shape. That way only dice inside the tray are read, and the rest of the image (desk, cables, etc.) is ignored.

Set tray region (polygon)

Go to Settings → Camera (or open the Camera calibration wizard).
Find Tray region and click to Set tray region (or similar). A live view with the camera feed will open.
Click on the corners of your dice tray in order. For a hexagon, click each of the 6 corners in sequence. For a round tray, 6–8 points around the edge work well. You need at least 3 points.
Confirm or save. Only the area inside the polygon is used for dice detection; everything outside is masked out.

If your camera is fixed and the tray doesn't move, you only need to set this once. If you change camera angle or tray position, run the step again to re-draw the region.

Using lighting boost

Lighting boost brightens the camera feed before dice detection. Use it when the image is too dark (dim room, shadows, or a camera with weak low-light performance).

Where to find it

In RollSight, open Settings and look under the Camera or Display section for:

Enable lighting boost — turn this on when your feed is too dark.
Lighting boost level — usually 25, 50, 75, or 100%. Start at 50%; if the image is still dark, increase. If it looks washed out or too bright, decrease.

Tip: Lighting boost is applied in software. For best results, also improve physical lighting (e.g. a small lamp or ring light on the tray) so the camera gets a clear, even image.

Other lighting issues (flicker, glare, shadows)

Flickering or unstable image: Some fluorescent or LED lights flicker at a rate that can affect the camera. Use a different light source (e.g. incandescent or a good-quality LED desk lamp), or move the lamp farther away. Avoid mixing very different light types (e.g. daylight and warm LED) on the tray — pick one primary source.
Harsh shadows: Position the light so it doesn't cast a strong shadow from your hand or the dice. A light slightly in front of or to the side of the tray, or a soft ring light above, usually works better than a single light from one side.
Glare on dice: Matte dice reduce glare. If your dice are glossy, avoid pointing a bright light directly at them; diffuse the light or angle it so the reflection doesn't hit the camera.
Lighting changes during the day: If you play in a room with windows, the light can change. Re-run Calibrate Background when you start a session, or when you notice recognition getting worse as the light shifts.

Dice read too early or while still moving

RollSight is designed to wait for dice to settle before reading. If it's reading while dice are still moving, or if you get inconsistent values right after a roll:

Wait for the read: Give the dice a second to stop moving. RollSight uses motion detection to know when the roll is "done"; if you trigger a manual Rescan while dice are still moving, you may get wrong or partial results.
Motion sensitivity: If rolls are being read too early (before dice fully settle), there may be a setting that controls how long the app waits after motion stops. Check Settings or the Camera/Detection section for any "settle delay" or similar. If your dice bounce or roll for a long time, you may need to wait a bit longer before the automatic read.
Rescan when settled: If the automatic read happened too early and got the wrong value, use Rescan (or equivalent) once the dice are fully still. That sends a fresh read to the VTT.

Small dice, overlapping dice, or many dice

Very small dice (e.g. tiny d6, small d4), dice that overlap, or a tray full of many dice can be harder to detect and read.

Small dice: Move the camera closer to the tray (or use zoom) so the dice take up more pixels. Ensure focus is sharp. Lowering detection confidence slightly can help small dice get picked up. If the camera has a high resolution, make sure RollSight is using it (not a heavily downscaled feed).
Overlapping dice: When dice are stacked or touching, the model may see them as one blob or misread. Spread dice slightly so they don't overlap. After a roll, nudge any that are on top of each other so each die is visible.
Many dice at once: RollSight can handle multiple dice, but a very crowded tray (e.g. 10+ dice) may slow detection or occasionally miss one. Use a tray that fits your typical roll, or roll in smaller batches. Defining a tight tray region so only the rolling area is in frame can help keep performance good.

Tray or camera moved — detection off or misaligned

If you moved the tray, bumped the camera, or changed the camera angle, the detection region and calibration may no longer match the image.

Re-draw the tray region: Go to Settings → Camera and use Set tray region again. Click the corners of your tray in the new position so the polygon matches the current view.
Re-run background calibration: With the tray empty and in its new position (and under the same lighting), run Calibrate Background again. That updates the baseline image RollSight uses to separate dice from the background.
Check zoom and rotation: If the camera was moved, you may need to adjust zoom or rotation in the Camera menu so the tray is framed correctly and not tilted.
Prevent drift: Secure the tray (e.g. double-sided tape, non-slip mat, or a fixed mount) so it doesn't shift during play. That reduces the need to recalibrate mid-session.

Slow or delayed recognition

If there's a noticeable delay before dice are recognized, consider:

Smaller detection region: Use the tray region (polygon) to limit detection to just the tray. Less of the image to process can mean faster results.
Camera resolution: If the camera is set to a very high resolution (e.g. 4K), try a lower one in system or camera settings (e.g. 1080p). RollSight doesn't need 4K for dice recognition, and lower resolution is faster to process.
USB and system load: Plug the camera into a direct USB port (not through a busy hub). Close other apps that use the camera or heavy CPU/GPU (browsers with many tabs, games, video editors). See USB and hardware tips.
Computer performance: RollSight runs detection on your machine. An older or underpowered PC may be slower. Closing background apps and ensuring the computer isn't thermal throttling can help.

Roll not sending to VTT (Foundry, etc.)

RollSight detects the roll correctly but nothing appears in your VTT (e.g. Foundry VTT).

Foundry module: For Foundry VTT, install and enable the RollSight module in your world. Check that the module is active and that its settings (e.g. URL or port) match how RollSight is configured to send rolls. See the Foundry VTT integration guide.
Connection: RollSight and the VTT need to be able to talk (e.g. same machine, or correct IP/port if remote). Firewall or antivirus can block the connection — allow RollSight and the VTT through. If you use Foundry hosted elsewhere, ensure the module is set up for the correct address.
Roll type / character: Some integrations send to a specific character or roll type. Check RollSight and VTT settings to see which character or sheet receives the roll, and that you're not filtering by roll type (e.g. only d20) if you rolled something else.
Confidence threshold: Rolls may only be sent when confidence is above a certain level. If your rolls are detected but not sent, check if there's a "send only high confidence" option and try lowering it, or use Rescan to force a resend.

Activation or license key issues

The app won't activate, says the license is invalid, or you lost your key.

Paste the full key: Copy the entire license key (no extra spaces or missing characters). Paste it into the activation field. Some keys are long — ensure nothing was cut off.
Internet: Activation usually requires an internet connection so RollSight can verify the key. Check that your machine can reach the internet and that a firewall isn't blocking the app.
Key expired or revoked: If you see a message that the license is expired or invalid, your key may have reached its end date or been revoked. Contact support or use the Support page to request a new key or check your subscription.
Lost key: Use the Resend license key form on the Support page. Enter the email address associated with your purchase and we'll email the key to you.

App won't start, crashes, or freezes

RollSight doesn't launch, closes unexpectedly, or freezes during use.

First launch: Ensure you have the latest version from the official download page. Install any required runtimes (e.g. Visual C++ on Windows) if the installer or docs mention them. Try running as administrator once (Windows) or allowing the app in Security & Privacy (macOS) if it was blocked.
Crash on startup: Disconnect the camera and try starting again. If it starts without the camera, the crash may be camera-related — try a different USB port or camera. Delete or rename the config file (e.g. camera_config.json in the app data folder) to reset settings and try again.
Crash or freeze during use: Note what you were doing (e.g. opening Settings, changing camera, after a roll). Try to reproduce. If it happens when the camera is active, see Camera feed issues and USB and hardware tips. Updating graphics drivers can help. Report the issue with steps to reproduce so we can fix it.

USB and hardware tips

General advice for camera and USB stability:

Plug directly into the computer: Avoid USB hubs when possible, especially unpowered hubs. Direct USB 3.0 (or later) ports usually give the best bandwidth and stability.
One camera at a time: If you have multiple cameras (e.g. laptop webcam + dice camera), only connect the one you use for RollSight when playing. That avoids confusion and frees bandwidth.
Cable and port: Use a good-quality USB cable. If the connection is flaky, try a different cable or port. Loose ports can cause disconnects.
Windows — USB selective suspend: Windows can put USB devices to sleep to save power, which may disconnect the camera. In Power Options → Advanced settings, find "USB settings" → "USB selective suspend" and set to Disabled for the power plan you use.
macOS: If the camera isn't recognized, try a different USB-C or USB-A adapter if you're using one. Some cameras need a moment after plugging in before they appear.

Still stuck?

If you've tried the steps above and still have issues:

Check the FAQ for more answers.
Join our Discord — the team and other users can help with your setup.
Use the contact form and describe your setup (camera, tray, lighting, OS) and what you've already tried. That helps us narrow it down.

Troubleshooting Guide