A video wall controller is a device commonly used in digital signage to control, well, video walls. It helps manage and distribute content across multiple displays.

Why use one with HeavyM when you can already manage multiple screens from the Output Setup you ask? One reason can be that you are limited by the number of video output ports (HDMI, DisplayPort, etc) on your computer.

Here's an example: let's say we only have one HDMI output port on our machine but we need to project on 4 projectors. A video wall controller will help us bypass that limitation: connected to our computer on one end, it will act as a splitter and help us cut the single texture into 4 different parts, then dispatch them to the 4 projectors on the other end.

Note: this example will focus on the Datapath Fx4 model but can be applied to other video wall controllers with similar behavior.

Setup in HeavyM

Output Setup

Since the idea is to cut and arrange our displays in the video wall controller, we will send a single big texture from HeavyM. In this example, we have four FullHD projectors (1920x1080), so we need to use a 3840x2160 (4K) texture.

1. In the Output Setup, set the Canvas size to 3840x2160.
   
2. Still in the Output Setup, if your Datapath FX4 is connected to HeavyM, you can find it in the list of Destinations. Ours isn’t connected in this case, so we can just prepare in advance with a virtual display: set the resolution to 3840x2160 and name it Datapath FX4 (optional).
   
    

Canvas Setup

The 4 parts will be arranged in the Canvas as such: 

Tip: there is no native grid tool in HeavyM at the moment. However, if you need to outline precisely the 4 FullHD displays in the Canvas, you can still create a custom grid in a separate locked Group to help place content precisely.

Setup in the Wall Designer

For a simple 2x2 video wall setup like our use case, the process is pretty straightforward. 

Add the outputs to the wall designer and then assign each region of the input to its correct output. Our layout is the default one for the Fx4 so we don't have to change anything else.

And that's it in our case!

For more complex cases, know that you can customize the segmentation of the input and the layout of the physical outputs, like this for instance:

Going further

Setup requiring edge-blending

If your outputs need to be blended together, it gets a bit more complex: as we are sending only one full output texture and not doing the output segmentation in HeavyM, it means that we cannot use the built-in screen edge-blending module. The blending of the outputs needs to be done after the segmentation in the wall controller (if your projectors support the feature) or before, inside the single screen. How do we do this then?

In this case, you can use the soft-edge feature of Players, in order to create a blending directly inside the HeavyM canvas. Here's an example of the setup with blending applied to our simple 2x2 use case:

The overall size of the texture we are sending (and thus the canvas size) and the segmentations do not change here, the edge-blending is accounted for internally. As you can see in the picture above, each region has to include an overlap of it's neighbouring regions.

To break down a source in four parts for four different players, you can use the Slice Selector. Here's a breakdown of how to achieve the setup in the previous picture:

Note: unfortunately, this "internal" soft-edge only works with Players, if you are using faces and group effects it is not possible to perform a segmentation with a blending.
 

Extending the number of outputs

That's it for our video wall controller use case. As mentioned, we are presenting a simple use case here, with a specific model, but know that it's possible to extend this concept to other brands or models with even more outputs. 

Or you can also combine multiple controllers to extend the number of outputs!