Blender School: Material Tips from Nico Linde

 While I wait for a long render to complete, let's do some Blender School.

Tips for perfect textures, every time

1) Always mix two textures to provide that surface variety and to help hide imperfections.

2) First material! If you are not unwrapping your mesh before applying a texture material, do the following node setup:

3) Use Node Wrangler to add a texture ( Shift+T after selecting the shader)
4) Use the generated coordinates and then select Box projection. For most regular shapes, this works fine.
Tip: Use the Blend parameter to soften seams. Also, add a value node and plug it into the Scale socket for quick scale changes.
5) Duplicate the first material and plug both shaders into a mix (colour) now. Change the texture of your second shader. Don't use the standard mix factor; instead use another texture map and use a suitable blending mode: 

Mix - Blends the two images together.
Multiply - Make the white parts disappear.
Screen - Make the black parts disappear.
Overlay/Soft light - Make the grey parts disappear.

Example: Use an RGB Curves node to control the contrast and brightness. Tip: Use Cmd + J to organise shader trees into frames.

Consider using three textures for hero materials.

Hero material (Colour only for simplicity)

Make Materials Smart

In the real world, materials change with shape. For example, metal edges get worn. Setting up edge ware or AO (ambient occlusion).

1) Add an ambient occlusion node and mix it into the colour output. Use an RGB Curves node and a maths Divide node to control its effect.

2) For a more substantial AO effect, take a dedicated AO node and pass it into a maths Multiply node using a Colour Ramp. This will add more realism. 

3) Take the material output (prior to the AO) and feed it into a Bump Node (via Height), then put the Bump node output into the shader's Normal input. Take care to set the distance appropriately; it usually needs to be very small.

Bumpy materials

Integrate the model into its environment.

Always consider how the model's surroundings will affect its surface. In a forest, there might be moss growing on the model. In a desert, there will be sand.

Luckily, this is pretty simple. Add a Mix Colour node. Use its colour picker to sample the environmental colour that you want to add to your model.

Environmental Colour mixed using a texture as the factor, tweaked using an RGB Curve 

Try to make the mask texture place environmental colour realistically, such as sand on surfaces or trapped in gaps.

Bonus option: Blend grounded objects into the terrain map using a Colour Mix node. Mask with a gradient. Consider controlling the gradient with a Blender empty to tweak the position very carefully.