Fix: Extra Blur With Liquid Glass Over Banuba Camera

Hey everyone 👋,

I'm diving into a peculiar rendering issue I've encountered while using the Liquid Glass package in conjunction with the Banuba Camera view on iOS. It's quite the visual hiccup, and I'm keen to share the details and explore potential solutions with you all. Specifically, the issue manifests as an unexpected blurry rectangle appearing beneath the Liquid Glass widget, even though the intended glass shape is rendered correctly. It's like having a ghostly frame around our glassy effect, which definitely isn't the look we're going for.

The primary Liquid Glass effect works beautifully, creating the desired see-through, blurred area. However, this additional, unwanted blurred background rectangle is the fly in the ointment. It sits there stubbornly, disrupting the seamless integration we're aiming for between the Liquid Glass and the Banuba Camera view. This issue seems to surface specifically when these two elements are combined, suggesting a potential interaction problem between the rendering mechanisms of the Liquid Glass package and the Banuba Camera SDK.

Let's break down the specifics, examine the environment where this issue occurs, and walk through the steps to reproduce it. By laying out all the details, we can collectively brainstorm and hopefully pinpoint the root cause and, more importantly, a solid fix. So, let's put on our detective hats and get to the bottom of this blurry mystery!

Environment

Before we dive deeper, let’s set the stage. Here’s the environment where this quirky issue decided to make its debut:

• Flutter version: 3.35.1
• iOS version: 26 (This seems like a typo and should likely refer to iOS 16, but let's keep the original information for accuracy.)
• Device: iPhone 16 Pro Max (Future Device, which makes issue reproduction more challenging)
• Liquid Glass package version: ^0.1.1-dev.17
• Banuba SDK version: ^3.0.9

These details are crucial because they help us understand the specific context in which the issue arises. Different versions of Flutter, iOS, and the respective packages can behave differently, so having this information ensures we're all on the same page. The versions of the Liquid Glass package and Banuba SDK are particularly relevant, as they are the primary players in this rendering puzzle. Knowing these versions allows us to check for any known issues or compatibility concerns in their respective release notes or issue trackers.

It's also worth noting the device being used, an iPhone 16 Pro Max. While the issue might not be device-specific, certain hardware or software optimizations on different devices could influence rendering behavior. Keeping these environmental factors in mind is a key step in our troubleshooting process.

Steps to Reproduce

Okay, so you’re intrigued and want to see this blurry rectangle for yourself? Here’s how you can reproduce the issue:

1. Initialize Banuba Camera view: This involves setting up the Banuba Camera either through its native implementation or via its Flutter plugin. The key here is to have the Banuba Camera actively rendering its view, as this seems to be a prerequisite for the issue to manifest.
2. Place the Liquid Glass widget above it: The next step is to bring in the Liquid Glass widget. You'll want to position it on top of the Banuba Camera view. A common way to achieve this is by using a Stack widget in Flutter, which allows you to layer widgets on top of each other.
3. Run the app on an iOS device: Now for the moment of truth! Deploy your app to an actual iOS device (or simulator). This is important because the issue seems to be specific to iOS rendering. Once the app is running, you should be able to observe the described behavior.

Expected Result:

Ideally, what we want to see is only the circular (or custom-shaped) glass effect blending seamlessly with the camera feed. The edges should be clean and crisp, with the blurred area confined to the intended shape of the Liquid Glass widget. The overall effect should be a natural-looking glass overlay on the camera preview, enhancing the visual experience without any distracting artifacts.

Actual Result:

Unfortunately, what we get instead is a bit of a visual hiccup. In addition to the expected glass shape, a rectangular blurry area appears beneath the widget. This extra blur acts like an unwanted frame around the Liquid Glass effect, drawing attention away from the intended design and creating a somewhat messy appearance. It's like a visual echo of the widget's bounds, and it's definitely not the aesthetic we're striving for.

By following these steps, you should be able to consistently reproduce the issue and confirm that you're facing the same challenge. This is crucial for ensuring that any proposed solutions are tested in the same context and that we're all working towards resolving the same problem.

Notes / Hypothesis

Alright, let's put on our thinking caps and dive into some educated guesses about what might be causing this blurry predicament. After observing the behavior and considering the technologies involved, here's a hypothesis that seems plausible:

It appears that the blur compositor or material layer used by the Liquid Glass package is rendering outside its masked bounds when another native texture view (in this case, the Banuba Camera) is behind it. This suggests a potential issue with how the blur effect interacts with underlying native views, particularly when those views are rendering directly to the screen using Metal or similar low-level graphics APIs.

This behavior might be related to how UIVisualEffectView, a common component for implementing blur effects in iOS, interacts with Metal-backed layers. UIVisualEffectView relies on the system's visual effects compositor to generate the blur, and it's possible that this compositor isn't correctly clipping the blur output when it's placed behind another native view.

To put it simply, the blur effect seems to be bleeding beyond the intended boundaries of the Liquid Glass widget, creating the unwanted rectangular artifact. This could be because the masking or clipping mechanisms within the Liquid Glass package aren't fully effective when dealing with the specific rendering context created by the Banuba Camera.

So, what can we do about it? Well, one potential solution could be to explicitly apply a mask or clipping layer to the effect view. This would force the blur to be contained within the desired shape and prevent it from spilling over into the surrounding area. Here are a couple of code snippets that illustrate this approach:

effectView.layer.masksToBounds = true
effectView.clipsToBounds = true

These lines of code tell the effectView's layer to clip any content that extends beyond its bounds. This is a common technique for preventing visual artifacts and ensuring that rendering stays within the intended area.

Another approach could be to render the blur inside a CAVisualEffectSubview that is restricted to the widget’s frame. CAVisualEffectSubview is a specialized view designed for hosting visual effects, and it might provide better control over the rendering boundaries.

By exploring these potential solutions, we can start to narrow down the root cause of the issue and hopefully find a reliable fix. It's a bit like detective work, piecing together the clues and testing our theories until we crack the case of the blurry rectangle!

Visual Aid

To help illustrate the issue, here's an image that clearly shows the unwanted blurry rectangle beneath the Liquid Glass widget:

This visual representation makes it much easier to understand the problem we're tackling. You can clearly see the intended circular glass effect, but also the distracting rectangular blur surrounding it. This image serves as a valuable reference point as we discuss potential solutions and evaluate their effectiveness.

Having a clear visual of the issue is also helpful for communication. When discussing the problem with other developers or package maintainers, being able to show them the artifact directly can save a lot of explanation and ensure everyone is on the same page. A picture, as they say, is worth a thousand words, and in this case, it certainly helps to highlight the visual anomaly we're trying to resolve.

Conclusion

So, there you have it – the mystery of the extra blurry rectangle! We've explored the issue in detail, from the specific environment where it occurs to the steps required to reproduce it. We've even ventured into some hypotheses about the underlying cause, suggesting potential interactions between the Liquid Glass package, the Banuba Camera SDK, and iOS rendering mechanisms.

The key takeaway here is that this issue seems to stem from a potential conflict in how blur effects are rendered when combined with native texture views. The blur compositor might not be correctly clipping the output, leading to the unwanted rectangular artifact.

We've also discussed some potential solutions, such as explicitly applying masks or clipping layers to the effect view, or rendering the blur inside a CAVisualEffectSubview restricted to the widget’s frame. These approaches aim to contain the blur within the intended boundaries of the Liquid Glass widget and prevent it from spilling over into the surrounding area.

The next step is to put these potential solutions to the test. We can try implementing the suggested code snippets and see if they effectively eliminate the blurry rectangle. It's also worth exploring the documentation and issue trackers of both the Liquid Glass package and the Banuba SDK for any related information or known workarounds.

Collaboration is also key. Sharing this issue with the wider development community, including the maintainers of the involved packages, can bring fresh perspectives and potentially lead to a more robust solution. By working together, we can unravel this rendering puzzle and ensure a seamless visual experience when using Liquid Glass with Banuba Camera on iOS.

In the meantime, keep experimenting, keep sharing, and let's conquer this blurry beast together!