Having your Unreal engine model automatically resize to match the web browser of the user streaming your model can significantly improve the overall user experience, as it allows your model to fill up more of the available screen space. Additionally, it ensures that no client side resizing is occurring which will result in a sharper image.

Unfortunately, the resize feature which worked reliably in Unreal 4.27, was quite unstable in Unreal 5.0 and 5.1. Different users were impacted by this instability to differing degrees. For some users, their models are stable most of the time, even when frequently resizing, whereas for other users, even a small amount of browser resizing could lead to the model crashing. Given this inconsistent instability, we implemented a change that blocked the sending of resize messages to Unreal 5.0 and 5.1 models.

With the release of Unreal 5.1.1 it appears that Epic has fixed this issue. We have adjusted our SDK code to once again send resize messages by default. This change will impact you differently depending on your web-client of choice:

  • For users of the preview client, resizing for Unreal will be the default going forward. Our recommended path is for users to upgrade their existing 5.0 and 5.1 models to 5.1.1 or later. However, we know that this is not feasible for all users.  For that reason, we have an option to turn resizing off.

    If you go into the Model Details menu for your particular model, and open up the Runtime Customizations submenu, and add an environment variable saying UE_VERSION = 5.0 (even if your model is 5.1.0), this will turn off resizing by default.
  • For users with custom clients, this change will not impact you until you upgrade to version 4.0.0 or better, of the SDK.  If you want resizing off by default, we would recommend not upgrading your SDK until you’re prepared to upgrade to Unreal 5.1.1, at which point we recommend upgrading your web client to the latest PureWeb SDK.