Iridescence in Designer?

maizzy

Hi! I've been trying to figure out how to do this all morning, but having no luck. Trying to make like a spilled oil on asphalt kind of thing, but I can't seem to figure out how to get the spec color to actually show up. How would you put a little colored shine into a substance? 





(ignore the asphalt texture - it's a place holder. haven't actually put any work into it yet)

(Also, I'm relatively new to substance and most of my learning so far has been a lot of trial and error, so it's very likely I'm missing something too obvious for me to properly word my google searches - sorry if this is a dumb-dumb question)

poopipe

The only way to get coloured specular into a metal/roughness material is to make it metallic

maizzy

Metallic helped! thanks! Here's where I'm at now in case anyone wanted to see this experiment: 





Not really sure if I want to do more or not yet; I've been looking at it too long today to know what else I'd want to do.

maizzy

Picked this up and fiddled with it some more. Much happier with the look, so I wanted to throw out an update in here because my last version looked fairly blah.

I also wanted to ask again for some help with colored specularity; I still haven't managed to make it show up (even though I am happy with the metallic output look, still curious and would like to know for future reference).  Am I missing a setting somewhere with the metallic thing that's supposed to let me tweak that? IS there a way to make the shine itself be red like it would be if I plugged in a red spec map to a v-ray shader? Or is that not actually a thing with PBR, so it wouldn't be included with substance designer? I'm thinking of holographic things and stuff like that that might be interesting to try to make.

sprunghunt

You can switch the shader of the viewport to a specular based model instead of using the metallic/roughness model. 

This will let you use a specular map instead. That will be closer to VRAY.

poopipe

The metallic map in the substance shaders effectively acts as a mask - anything white will allow coloured specular reflectance (taken from Basecolor)and sets the basecolor to black, anything black falls back to a reflectance value of plastic. If you want a coloured highlight you need it to be metal. 

Going to spec gloss allows you to break this dependency, it's good because it means you can put correct values in for  weird materials like gemstones and use the correct values for things like concrete.
In practice however,  game renderers make so many optimisations and have such crappy lighting you can't tell the difference between one dielectric and another  so it's all a bit moot.  

Anything weird like gemstones, skin, fabric, holograms etc is going to warrant a special shader to overcome the limitations of your average renderer so you tend to need to treat them a bit differently anyway and that takes you out of the 'pbr' system. 

alsar

This is so cool! Can you please share the way you make your iridescence texture?