Select the model and add a new material to it
Let’s make a curvature map
Add gradient texture and color ramp
Click Control + T on the gradient to use the node wrengler and add a texture coord and mapping
Now if we control + shift + left click on the color ramp we can see how it looks like
rotate the color gradient Y to 90 deg
set the location X value to -0.58
now invert the color ramp
Now it’s time to connect the shader to the material
select the principled BSDF and clontrol + shift + click
Done
Now we want to create several more masks. Select cycles because they predominantly work with that renderer
Let’s add a geometry not and color ramp to our shader
connect the pointiness to the color ramp
Add a gamma node
Add a math node set to multiply
add a noise texture node
Let’s connect the nodes
Done
Now we create an edge mask
This is the list of new nodes. Note the dot product is part of a vector math node.
Setup
Add a noise texture and a map range
Setup
Setup
Done
Now we create the ambient occlusion mask
We need these nodes
Setup
Let’s now use our masks
We start with the ambient occlusion
We add two mix to the ambient occlusion
We add two colors in the second mix and then we need to connect the two mix to the main one that we have used to mix the main two colors going into the princiupled BSDF
Now we can combine the curvature mesh into the design
We need other two mix that are going in series to the ambient occlusion paths
We then plug the multiply node into the factor of the two mix
We set the two new mix to a very light color
We now need to plug in the edge mask. We need another mix in series to the principles BSDF. We plug the edge mask into the factor of the mix
Overall shader design
Now we need to setup the metallic and roughness of the material
We plug the edge mask in the metallic value
For the roughness we need three new extra nodes
we plug the edge mask into the top ramp factor
the ambient occlusion goes in the bottom color ramp
Setup of the two color ramps and mix
We can add some randomness to the roughness by adding three new nodes
Setup
Lower the mix value
Now we add the bump due to dirtiness
We will plug the ambient occlusion directly in the bump
the bump is then plugged into the normal of the principled BSDF