The template's pixel density should match, or preferably exceed, the projector's to enable a 1:1 pixel density. This requires knowing precisely how the UV coordinates have been mapped to the 3D model. If the aspect is calculated incorrectly the rendered content may appear stretched across the projection surface.
The template's aspect ratio should match the UV map's to enable square pixels. The template's resolution is calculated from two variables: aspect and density. The UV map is rendered into a content template to be placed as a background in Adobe Photoshop, Illustrator, After Effects or any other image / video editing application. Normally the projection surface is unwrapped into a texture that the content creator can generate video content from, in a similar way to how artists texture 3D models in the video games industry.
