ARFX Multiscreen Camera Actor

Section 3. ARFX Multiscreen Camera Actor

The ARFX Pro Multiscreen Camera Actor is a variant of our ARFX Camera that does the perspective warp to multiple displays at once on a single machine. These displays can be discreet and separate, in cube-like shapes, or even in flat curves. So long as they are far or angled enough from your main display, then the Multiscreen camera is the one for you.

There are other requirements, but so long as each display you wish to render on is stitched together to create one single screen (typically by using Mosaic), we can output to them using a single Viewport of the Unreal Editor!

Important

Only one ARFX Multiscreen Camera can be in a scene/level at once

A freshly placed ARFX Pro Multiscreen Camera!

Section 3.1 Exposed Settings

The following can be found within the Details panel when the camera is selected. Since this camera is a variant, please refer to the ARFX Camera and the Exposed Settings section found within the article.

There are only two settings that differ from a normal ARFX Camera.

Section 3.2 Views

Thankfully, you do not need to fill this out manually…

This setting is the actual list of points of each individual 3D plane that makes up a single “view”.

But what is a “view”?

A view is the virtual representation of a single facet of your physical stage’s display in dimension, position, and orientation. As you can see in the example image above, we make use of several variables that make up each screen and there is more you can do depending on how complex your stage setup is. Thankfully, you do not have to use this to manually construct your virtual stage.

Section 3.3 Importing from the OBJ file

The first way to import your display stage is by an OBJ file.

Before the add and empty buttons, at the top of the Views list is a button with 3 dots. Clicking this will open a dialog asking you to choose an OBJ file to import. This file is a 3D object that can be created in most 3D authoring software, and we have a tutorial on how to do so in the open-source Blender. Please refer to the How to Manually Create a Multiscreen View Model Section for more information.                    

Section 3.4 View Generation

Our easiest method to produce your Views list!

The above inputs, when generated, create this screen on our camera!

Below Views is this setting along with a “Generate” button. Expanding it will display something like the image above. With this you populate each segment of your screen in a particular manner to then generate the Views that was detailed previously. There are limitations, however.

It can only create a single interconnected screen. This means that you cannot create “floating” segments that are separate from the rest of the model.

• You cannot create floors or ceiling segments. Again, like the first point, it must be a single unified panel that goes from left to right

• You cannot create panels of varying heights.

If your needs fall within the above, then your only choice is to create an OBJ file. For more information on this topic, please visit Multi_ViewsGenerator

Section 3.5 How the Views Are Made and Their Theoretical Limits

Each view segment in Unreal technically has its own separate internal viewport. A good example to think of is how split screen works in multiplayer games or even picture-in-picture on TV programs. Unreal treats each viewport as its own separate graphics window that it must render sequentially.

Unfortunately for us, this sequential method of rendering causes a delay that grows exponentially as more views are added to the stack. At around 5 or 6 views, you will begin to notice a heavy toll on the frame rate of Unreal as it begins to wait longer and longer for the other views to finish rendering before moving on. This is especially a problem if the scene is heavy to begin with.

We are currently looking into optimizing it (possibly with multi-GPU support), but until then, keep this rule in mind:

Important

Keep your view count as low as possible.

At best, use as many as your system can handle, then scale it back a segment or two to give yourself overhead.

Section 3.6 Examples of ARFX Multiscreen Configurations

The rest that follows are examples of actual multiscreen setups we at ARwall have actually done for our clients in the past!

This stage comprised two LED panel walls, approximately 6 x 3.5 meters (or 2 x 12 feet), that took up the corner of their space.

This was a small test case we implemented for a client with 3 panels that made up two walls and the floor. As an aside, we found that our clients never actually used their floor panels if they had them installed.

This massive wall is actually an example of a curved screen. In total there are 7 column segments; 6 on each side are 50cm wide with 2.5° increments and a single massive flat wall that is 9m across (totals to around 12 x 3.5 meters or 40 x 12 ft). This is likely the absolute limit that our camera can go on current hardware while still being usable in a filmmaking space.