Step 4. Dirty air
It was time to create atmosphere in the scene and since this one is taking place deep underground I had to add the dust and fog that fills the air in these caves. A large sized brush, with a soft edge, on a new layer did the trick here. I set it at a low percentage of opacity so I could build up the densities of the dust in different areas of the cave. If I went too heavy on the brush work I could always play with the opacity property of the layer to get it right.
I also remembered to leave a patch clear enough so I could add in one of the focal points of my image later.
The more dust you add in, the further away an object gets. Even in broad daylight. Play with this technique to add depth to your scene
Step 5. Light from below
Light gets everywhere, even in caves. So using the previous technique and with a brighter sandy color, I add more dust on a new layer set to Color Dodge to depict light bouncing up from the depths of the cave. It gives the foggy atmosphere a little more interest and color.
The dust in the air picks up any light that might be bouncing around the cave
Step 6. Foreground elements
On a new layer, I added a rocky platform in the foreground for my two cavers to stand on. I used a hard edged brush with the dark brown color I used earlier. I turned off the layers necessary to get to that dark brown and use the Eyedropper Tool. It helped to keep my colors consistent. I used it at full opacity to block in the shape and then I used a textured brush with mid-opacity with the color picked from the dust around it to give it its rocky texture. This indicates it is catching some of the light in the cave.
In this scene, the closer to the viewer the rocks are, the further away from the light they are and thus, get darker.
Always think about the depth of the scene when trying to create believable environments. Think about the light, fog or haze as things get further away or closer to the viewer
Step 7. Damaged buildings
This was when keeping everything on separate layers became useful. I had to add damage to the faces of my buildings. I went into my library of references and textures and found a rocky texture and a rusty texture. These are free to use textures you can get at any good texture website.
I was able to turn off all the layers down to my windows layer, then used the rocky texture in Overlay mode and used the Transform tool to place it over the building on the left. I didn't have to worry too much about this building as it was going to be covered up mostly by the dust in the air when I turn the layers above it back on. However, the rusty texture had red and orange colors in it and more of it was going to be visible through the layers above it.
I de-saturated it (Alt + Shift + Ctrl + B on Windows), lightly erased the central area of the texture, and placed it over the building on the right. Then I set it to Vivid Light blending mode for the details on it to pick up the white of the building underneath it.
Textures are a great way to add believability to the subjects of your paintings