Fabric shader basically uses 3 differently tiled and rotated (90 degree) though the same black and white texture which is used to mix colors afterwards (this is something I really like as long as I can accept this fabric structure because I don´t need to search for thousands of different fabric textures in various colors, I just add the color combination that I like and try to match it with mixing colors :) . The reason of using 3 mixed textures is that altough the basic texture is seamless and tileable it is veeery easy to spot the repetition on objects and this approach hides it at least a little..In corona mix texture I use basic mix option with mix mask. Then there is falloff in composite map with texture on top so that a falloff is not so clean (this is approach seen for example on eduard caliman fabric shaders, then another composite map layered like this - basic diffuse texture, lifted diffuse texture for falloff property (I use here output map not color correction - it is easy to tweak contrast and brightness even vith curves of previous composite textures because in this case I would otherwise need to tweak each texture individually and this option just add this editing option on the top of everything), then this texture is of course masked with falloff with variance and last layer is just some dirt texture to give a little more color variation to the surface.
Then there is AO map which should produce effect of darkening the fabric in cavities and edges ..this is something I spotted for example on Bertrands´s shaders
For bump I use simple composite of wrinkles map and contrasty fabric map (of course everything BW) ..So in the end it is just diffuse and bump :) it is more about experimenting with each map intensity to produce shader that is believable
Brushed aluminium shader consists of two blended materials – one represents brushed coating and one anisotropic material masked with falloff map. Both materials have falloff map plugged in refl. color slot and fresnel ior turned off (999) , diffuse element is absolute black. Brushed material has simple aluminium texture plugged in refl. glossiness slot – when trying to match real world references I tend to use a little trick of Grant Warwick (I like how logically he creates shaders ) it goes like this – Observe real world reference and try to match basic refl. glossiness value just by playing with number from 0 to 1 ..When you are as close as possible plug in the map so that it can control the glossiness amount and play with output by enabling color map and tweak brightness and contrast in black and white mode. When you think you are close to desired result, in map rollout turn off and back on refl.glossiness slot to see if previously eyeballed glossiness matches with map controlled one. And if not tweak brightness and contrast even further. To simulate brushing I use normal map created from glossiness map.
Antique brass consits of two blended materials of different glossiness (but other than that they are pretty the same materials – this is step where it might be simplified – by not using blend as corona has ggx reflection model implemented) . The approach uses the same logic as above – firstly try to play with basic material glossiness and here even with reflection color as observed in real world antique brass material. Then there comes detailing of refl. color falloff map as antique brass has kind of brushed structure. This is represented by two mixed bercon noise textures – each with slightly different rotation (of 3 degree max) as the veins don´t go perfectly in ortho directions and I like bercon noise feature of distorting the noise map with another noise map and that is what I´ve done here with reflection color. Before plugging falloff map in refl. color slot I tried to implement another important property of this material and that is almost black or at least very different and darker color in cavities and edges – this is represented by ambient occlusion map – when occluded displays material as noisy mix between darkened basic refl. color and almost black – here you can experiment as long as you wish based on reference you are trying to recreate. I didn´t like the perfection of AO distribution in cavities so I plugged in noise map to control AO distance. Now I should have my refl. map finished and what I like before applying it to material is to apply this final step (AO map) in the diffuse slot of basic matte corona material – you get very good idea of what´s happening on the shader and have chance to control the parameters until you are satisfied. For bump I like to use bercon noise with distortion because it adds to realism of the shader with slight imperfections to the surface. I used composite map of scratches and noise basically. And that´s it.
Copper uses the same approach as antique brass with slightly different maps that represent its properties the best (just search through the internet) What is maybe a bit different here is that I experimented with diffuse element to add color variation to the surface (but other than that I let the diffuse element black when creating metals)
Scratched chrome uses approach seen on Viscorbel website.. Very simple – create scratchy chrome with hand painted map in photoshop or just some from the internet and then create clean metal – and mask them with falloff set to fresnel .
Wood textures – Each of them consists of diffuse (textures from admira edited in photoshop to make them seamless and tileable) refl. glossiness and bump. Either way they are represented by the same map or slightly different in terms of brightness and contrast.
I hope I made things clearer with this post. I am really thankful that there are artists among us who want to share their valuable knowledge. So I take no credit for myself :)
