Image mockup AI generator or manual mockup guidance

Hi there, I'm a pattern designer (in the wallpaper industry) and when I have a pattern swatch in Illustrator, I'd like to apply it to a blank wall in a photograph to create a realistic mockup that shows it at the proper true scale. 
 

This will easily show potential buyers what the pattern swatch sample would look like on the wall, if they were to buy it. How can I make this happen and have it appear true to size? You can look at examples on my site of mockups that were manually sized but the scale of pattern is estimated in the photo. Http://muscatodesign.com
 

Designers and Developers: Are there AI generators for wallpaper/pattern illustrations? I know some people use AI to create a pattern itself, but whether it's created manually in Illustrator - or by AI, I'm curious about showing it in mockup format at true scale. Thanks for any help!