When receiving an NDI stream in Unreal Engine using the NDI Unreal Engine SDK, you may see a no data indicator (sometimes a red square) or the incoming video may fail to display. The stream may appear selected, but the receiver never renders frames or the connection appears correct, but playback does not work.
In most cases, this behavior is caused by how the receiver is set up in the level and Content Browser, rather than an issue with the stream itself.
Our recommended fix is to use an NDI Receiver Actor in the level and configure the stream using an NDI Media Receiver asset.
Setup
1
Add an NDI Receiver Actor to your level
An NDI Receiver Actor behaves like a screen in your scene that renders an incoming NDI stream.
2
Create or assign an NDI Media Receiver asset from the actor
By default, the actor does not have a media receiver asset assigned. In the actor’s NDI IO settings, you can either assign an existing NDI Media Receiver asset or create a new one. Multiple receiver actors can share the same receiver asset.
3
Configure the stream connection in the NDI Media Receiver asset
Open the NDI Media Receiver asset in the Content Browser and set the Connection (NDI source). This asset stores the stream selection used by the receiver actor.
4
Play the level and allow initial connection time
Once configured, the receiver typically starts receiving when the level begins play. Depending on your setup it may take a moment to initialize, especially on first connection.
You may not be getting data for other reasons. For instance when creating receiver assets but not associating them with an NDI Receiver Actor in the level or vice versa. Or if you are expecting an “open” action on an asset to behave like an in-level receiver surface. The first time a level starts receiving you must wait for initialization after entering Play.
If you continue to have issues please check the following:
The NDI Runtime is not included with the Unreal plugin.
Ensure that the stream still works with Studio Monitor on the same PC as Unreal. Open up Studio Monitor (part of NDI Tools) to confirm the video is there.
The Receiver Actor allows enabling/disabling audio, color, alpha per actor (these affect only that actor). If you disable required channels, you may not get expected results.
