Real-Time or Pre-Rendered?

Real-time graphics are drawn while the show runs. Pre-rendered ones were finished days ago and only play back. Clients often ask for real-time because it sounds advanced, and they often don't need it. Sometimes they do.

The test

Ask one question: does this content depend on something you can't know until the moment it happens?

If it reacts to a presenter's timing, live data, an audience vote, a camera or an object on a table, it has to be real-time. If the same pictures would play the same way every night, pre-render it. You'll get more polish for the same effort, and it'll play back the same every time.

What real-time gives you

• Response. The picture follows the show rather than the other way round.
• Late changes. A colour, a name or a number can change at rehearsal without a render.
• Resolution freedom. It draws at the size of the wall, which helps on very wide canvases.

The tools are mature. Notch Blocks are self-contained single-file exports that run inside media servers such as Resolume and disguise. TouchDesigner is widely used for this work, and Unreal's nDisplay synchronises several machines so that all of them render the same frame at the same time.

What it costs

• A frame budget. Every effect has to be drawn in time, every frame, for the whole show.
• More ways to fail. A dropped feed or a slow machine shows up live, in front of everyone.
• A skilled operator. Somebody has to be able to fix it in the room.

None of that is a reason to avoid it. It's a reason to plan fallbacks and a freeze from the start.

Often the answer is both

Most good shows mix the two: pre-rendered backgrounds and hero films for the moments that have to be perfect, with real-time layers only where something really needs to respond. If you do pre-render, ask the operator first what the server wants.

For the BYD Seal 7 launch, we built a real-time visual show for an 11K ultra-wide curved LED. Our object recognition table has to be real-time by definition, since nobody knows what's going on the table next. Tell us about your show on our live events page.