TexturePaint3d

Texture Paint 3d is a soon to be released 3d object texturing and painting app in desktop or VR versions*

Paint 4k textures.

There is a free demo version with some restriction.

Load in a UV mapped 3d object and Paint using PBR textures  from the built in selection or create your own custom textures. **

Paint with effect brushes like wet paint, metallic, matt,  blur, smudge, lights, use different brushes and many more. 

In the desktop version you can create a real time  curvature edge mask to add effects like worn edges ( Not available in VR version)

Import existing textures on to your model ( Colour, Normal, Metallic, Emission.)

Export your modified textures  ( Colour, Normal, Metallic, Emission.)( Full version only)

*There are a few differences in the VR toolset from the desktop ones.

** Objects must have a single UV map and material for best results.