BLENDING (UCP BUILDING)

 I opened a UCP building picture which I want to add 

rough/dirty wall to its’s side (blend). Then opened 

another picture (grungemap) which will be the 

rough wall. I tried to move the rough wall by 

dragging it to the UCP picture page but was unable 

to.
  

I then selected it, copied and pasted it on the UCP picture to achieve this picture. 

I selected the rough wall then checked the show transform controls on the menu bar to resize the wall to fit the side of the building picture after which I reduced the opacity to 59% to be able to see through.

Then, I clicked on switched between free transform and warp modes on the task bar to be able to resize to fit in the side of the building wall. When I can see that it fit perfectly well, I checked the tick sign beside the free transform and warp mode to achieve this: