I'd like to map part of an equirectangular image to a cuboid mesh, in order that the texture view from an arbitrary POV appears without distortion. Both the mesh and its uv layout will be used for a projection mapping environment, hence the question.
The image below shows the mesh, and a proxy sphere to mark the location I'd like to view the equirectangular image without distortion.
I'm using Blender's spherical uv unwrapping, which is close, but I can't see any controls exposed to allow me to translate or scale the spherical projection itself. Note that I'm not talking about scaling or translating the UV islands, after projection. Instead, I want to control the position from which the spherical projection itself is centered.
For reference, Maya uses a manipulator tool to position and scale spherical UV projection.
I'm hoping there is a way to translate and scale spherical projection in Blender, similar to the Maya example.