There's nothing really hard to model in this scene

Walls: I simply used box and planes and edit them, extrusion for the window and the door

The ground: I used A small plane and I extruded its edges for ground and edited it to model the stairs, the rest is obtained by a displacement map

The planks: I used chamfered box with extras edges to deform them

Other details: The wires are renderable splines, the grass is made with Grass-o-matic and stone with geospheres with a noise modifier ( the vespa was found on the net )

General Tips

- For most materials I used the Oren-Nayar-Blinn shader, because it has diffuse level and diffuse roughness channels that allow more control over the diffusion of the color, that's very helpful to add dirtyness, hide the seems of the texturemaps (if there are any) or darken some part of an object (Raytracing and multi-layer shaders have also diffuse level and roughness channel)

- The UV-channels are very important and I use them massively to manage my differents texture maps and masks. I use differents UV-modifiers with diffrerents channels (1, 2, 3...) to manage my maps, I rename each UV-modifier to the name of the corresponding maps, for example : UVW mask, UVW Moss, UVW cobblestone...

- To easely tune maps, luminosity, contrast and color I use the Color Correct freeware plugin

- I often use mix maps and blend materials with masks, it's a good way to get complex mapping with a few basic maps. I prefere blending my textures in max rather than in photoshop because it's easier to manage masks and move them.

I will show the making of two materials now: one complex and one simple, it represents the two kind of material I used in this scene.

General Tips

The ground material will be done in three steps, first I create a mix between a ground and a mossy map using a mask, secondly I create the cobblestone material and thirdly I blend them together using another mask.

At first, I make a screenshot of the UV-editor to use as a guide to paint my mask and a part of the diffuse level channel

 

 

I mix a mossy map and a ground map with a painted mask using the mix mapto create the diffuse map.

The bump map is a bit more complex, I mix both bump maps corresponding but the result does not perfectly match because the moss bump is darker than the ground, it will look like sinking into the ground. To correct ithat, I again mix the with the previous mix and a negative image of my mask. I get an appropriate bump map, the moss is lighter than the ground so it will emerge from the ground:

I painted in black the base of the walls and the stairs to darken them, I mixed it with an other dirt map to add details.

The cobblestone material is simple, he has just diffuse, bump and a diffuse level to add dirtiness

The final material is the result of three textures, moss, ground and cobblestone with differents placements rules by masks

The brick walls, concrete wall, wooden door...

These shaders are quite simple, I use color maps and bump maps, diffuse level and diffuse roughness maps to add dirtyness or modify the contrast of the maps like the concrete wall, the two colors on the wall are created by using a diffuse level and diffuse roughness maps to darken and ligthen some parts of the wall.

I often use color correct to edit mask because it's much easy and powerfull than use te output panel oft the map.

The diffuse and bump maps are obtained by mixing with the same mask, I decreased the contrast of the mask to make the second map appear more softly:

The diffuse level and roughness are the same maps obtained by an RGB multiplier map using a gradient ramp and a dirt map. The diffuse roughness ligthen map with its white values and the diffuse level darken the map with its black values. The values do not have to be too high if not you will alter too much the maps, the effect must de quite subtle.

I would like to say a thing about lighting too: there's no GI, the skylight is created by about 15 spotlights with depht maps shadows, and there's about 15 omnis with decay and custom colors to simulate inderect ligthning.