Displacement map question

I got a building model with few easy to model box windows holes in walls. But in my model i got those windows flat and just textured. I got it textured and now it there a way that if i make a disp map will those windows be displaced inwards? And what map should it be since i want them displaced inwards not outwards?

up nobody knows?

I cannot really understand why you would want to make a displacement map of such a thing. A displacement map pushes both inwards and outwards if the mid grey is set as zero. To get anything anywhere decent looking you’ll have to have a huge poly count to render.

Perhaps the quickest and the dirtiest method is to cut around the window and just extrude it back into the wall face a little.