Isolating normal map details for painting

[Eranekao]

Hi all! I have this high-poly table leg on the picture. The floral ornaments are currently a mesh, but I want to bake them on a low-poly as normal map details. I want to paint the ornaments with a gold material. So far so good. However, the pic is just a sample and they are quite long, x4 per side x4 legs. To paint them manually would be a huge waste of time. I can't overlap UVs because I want to bake AO for the whole table too.

Is there any way to mask only the baked ornaments? Or is there a fill tool that will fill the protruding details only? I'm using Blender: I was thinking about using an ID map, but I'm not sure how to bake one that has a different colour for the ornaments vs the leg itself. Any suggestions?

[Eranekao]

Here is the picture:

[justaviking]

Is there any chance a "Height Map" could be used as a filter?  The background around the vine looks very flat, so it should all be the same grayscale color.  Perhaps using a "Level" adjustment on the Height Map could help you make the background black and the rest of it white.  At least enough to make the painting easier.

[bruce_4]

Open up the high res mesh in Blender and export the UVs of just the detailing polygons you want to be gold.  Adjust the output image in Photoshop (or your image editor of choice, you could even do this entirely in Substance Painter with simple levels adjustment) and turn it into a Mask.  Then apply that mask to a gold layer and that should paint the detail.