Sorry if this has been asked before but I couldn’t find anything doing a search.
I have a jpg image placed as a background in one of my orthogonal viewports and would like to dim it down a bit. The transparency and alpha mode options on the viewport\back tab are greyed out. I’ve tried other image formats (tga,png) but still can’t use the transparency option.
I have used this before but just can’t remember the details. What am I forgetting?