I have a obj model that I imported into blender. The model is a render of a city so its fairly large. As can be seen from the stats in screenshot below (this is after decimating with a ratio of 0.5)
I also have the texture file for it in png format and I want to map this texture onto the model in blender.
Below is the image I want mapped on the model:
Ive watched a number of tutorials on how to do this and all direct towards changing the material from base color to texture image and then using UV editing to wrap or unwrap the texture onto the model, but the tutorials show cubes and simple objects and when a face of the model is clicked the region of texture is shown that its taken from. But thats not happening in my case, maybe due to the large number of vertices?
See below the screenshot, on the right the model is zoomed in to show what I mean and nothing is being mapped (other than a solid green color)
How do I get the texture mapped onto the model?
Thanks
Update:
Adding the attempts screenshot based on suggestions in answer:
UV Mapping
World Coordinates
edit
Updated model: