NVIDIA Mosaic
Note: Before starting the Mosaic setup ensure that for the Christie Captiva projectors a custom resolution of (1280 x 720 @ 120Hz) is used. The default 720p or 1280 x 720 resolutions might lead to problems after engaging Mosaic. Please make sure to go through the steps of the Nvidia Settings for projection VR page before continuing here.
From the Nvidia control panel go to Workstation > Set up Mosaic
Select the topology that matches your setup
Under Select Displays, click the checkboxes next to all displays in the projection system. Ensure that the Refresh rate (typically 120) and resolution are set according to what your projectors support.
Arrange displays by dragging and dropping each panel to the proper location matching the numbers displayed by each projector. Click Apply to save changes, then click Finish.
Finally verify the resolution is set to 1280 x 720 for the Christie Captiva projectors and the refresh rate is set to 120Hz.
Nvidia Mosaic documentation: