You can bring up the 3D Stereo Options by doing any of:
Opening up the window from the main toolbar's
RMB->Window->3D Stereo Options.
mrViewer supports a 3D Stereo Options window to control all aspects of your 3D Stereo and VR experience.
The VR 360 Sphere button allows creating a spherical panorama view of 360 degrees of the image or video currently being shown.
The VR 360 Cube button allows creating a cubic panorama view of 360 degrees of the image or video currently being shown.
The other options are two: Input and Output.
The Input option allows you to select how the stereo is encoded. Currently this can be in Separate Layers (OpenEXR) or images, Top/Bottom in one image (half) and Left/Right in one image (half).
The Output selects how the 3D is shown on the mrViewer window. It can be No Stereo Output, Left View, Right View, OpenGL Stereo (not working), Top/Bottom, Bottom/Top, Left/Right, Right/Left, Even/odd rows, Even/odd columns, Checkerboard pattern, Red/Cyan glasses (Anaglyph), Cyan/Red glasses (Reversed Anaglyph).