Finally got time to do some more texturing for Tube : Concrete walls !
Note that the render above is not a ‘shot’ or anything , it’s a test render with some simple light, no comp or set dressing , just to check how these materials are working toghether.
I painted a custom unwrap dirtmap for the tunnel , reused that for a background wall , and painted a generic dirtmap for the wall in bottom left of picture (generic as in : it’s tileable on X with areas of damage on top and bottom )
I used used Blender texpaint for the 1st pass and Gimp to refine the maps with more complex/’realistic’ brushes (simulating paint strokes or scratches..).
Then in Cylces nodes i used the dirtmaps + a concrete diffuse base texture (for clean concrete , but used also for dirty parts , just made darker by blending with a gradient controlled by the dirtmap) And a bumpmap for the dirty/broken/rough concrete areas.
Specular channel was derived in nodes from the diffuse (using a “less than” node to extract dark diffuse spots as bright speckles in speculars)
Below , screenshots of the components and ‘finals’ (before comp) :