Specular color help
Hey,
Is there a place I can find generic "specular colors" for different types of surfaces? say for like, wood, stone, cloth, skin... etc
Thanks!
Is there a place I can find generic "specular colors" for different types of surfaces? say for like, wood, stone, cloth, skin... etc
Thanks!
Replies
Seriously, though, it's a mixture of artist interpretation and just how things look. You don't need to have a list of what colors stones are, do you? Why do you need it for their spec? Just look at some ref, and play around with it until it looks how you want it to.
Since specularity is shine, you sometimes want to mimic the environmental colors not the material color. For example if your shinny metal object is outside on a bright blue sunny day the spec color might be a blue-ish color to mimic the sky. Of course the material type and color play a big role but you have to factor in what is making the shine.
Pior has a good tutorial about generating spec maps.
http://pioroberson.com/tuts/tut_texturing_tricks.htm
But really the best thing you can do is just adjust the hue/saturation on your defuse texture and keep playing with it till you get a good feel for what colors do what.
Specular is a quick way of simulating that reflection in computer world. So generally specular colors would skew toward the light's color. Really strong lights will overwhelm an object's diffuse color.
There is no "generic" specular color that you can always use with any surface. The amount of specular is more important than the color of the specular in conveying the type of surface. Specular color is more of an artistic choice. Remember that the surrounding color also changes how you perceive a particular color.
Well plastic would have a white specular, not an orange...
But in addition to the artistic aspect, don't forget about the technical- the specular of skin is bluish/greenish because if it were red/orange/white, it would look yellowish as the result. The fact that it is bluish/greenish counteracts the reddish skin tones and results in a more white specular color skin should have (white/colorless due to the skin's oils).
Vig, you keep saying defuse when you mean diffuse. Unless you have explosive textures that you need to disarm?
[/ QUOTE ]My Co-Workers: "BOOM! Hahaha Vig mixed up the green and red channels again didn't he? I keep telling him clip the red but he never listens..."
Such a bad habit to break. I don't know what it is about training my brain to use the OTHER middle finger when typing that word. I blame all those years of counter strike.
Anyway, we digress.
[/ QUOTE ]The problem is... Per doesn't...
I think something incorrect like plastic specular color being the same as it's diffuse color, when plastic specular should be white, needed to be pointed out.
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I disagree. A lot of game art I've seen uses colored specs on plastic, and it looks incredibly convincing.
Considering we don't have the ability to use complex shaders for each and every individual surface, sometimes it's okay to bend the 'rules' with spec and use an unrealistic color to better define the material. Spec's just an artist's tool, there isn't some scientific correct way to color something.
oh and also I would definitely use white for most bare metal so it reflects what's actually seen, with no modifications to the color
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I like using somewhat complementary colors, if I don't have a env map or anything for reflections. I think it sells the depth/reflectivity of the surface better, most of the time.
/offtopic, whatever.
http://ecx.images-amazon.com/images/I/419Z49THBDL._SS260_.jpg
Feel free to find your own photos. And a photo of orange with orange specular and orange with white specular. I'll let you decide what looks more like plastic.
Again, it goes down to both knowing what specular is, and how it is done in CG. Plastic will have a white specular because it is very glossy. And by glossy, I mean, it is 'shiny' but not 'reflective'. It reflects light from the environment, but is also micro-bumpy so it is not 'reflective.' It is 'glossy' so it has a white specular- or its specular is whatever color the light is (or even better, use a cube map to control your specular). "Latex" would be the same way. And so is true of anything waxy, whether fruit or skin. Skin is a unique case more because we pay extra attention to it, so we adjust the specular color to bluish/greenish so the highlight doesn't look yellowish, as explained above.
The only reason you would want a diffuse-colored specular for plastic is a really rough approximation of SSS which would be seen at the edges of the specular hotspot. But this would probably not be handled via the specular color, it'd be a lighting model.
Anyway I could of course be wrong, but I'd like some examples to back up what Per has said.
Skin is a unique case more because we pay extra attention to it, so we adjust the specular color to bluish/greenish so the highlight doesn't look yellowish, as explained above.
[/ QUOTE ] It's another deal completely why people use a color spec map for skin. If you want one color of blue spec just use a B/W spec map mask why bother with a spec color map.I wouldn't lump skin and plastic into the same category I wouldn't even put them in the same example, I wouldn't even bring it up in this thread. The poor guy's head is swimming enough already. Since plastic is normally the same depth and color across the entire object you might as well stick to a B/W spec map and let the lights provide the color.
Skin on the other hand is very complex in its layers, opacity and colors. Since you have varied depth and color you want to avoid white spec in certain areas while putting it in others. Doom3 skin looked like plastic because the spec was the same color and opacity. You don't want to apply pink or blue to areas that will be another depth and another color. For example on the cheeks (fleshy and often flushed with blood) you might want a blueish color to play off the red. But on the cheek bone you might want something closer to white as it won't be as fleshy or thick and isn't the same color as the cheeks.
The top most layers of skin are translucent and as you get into the different layers of skin, fat and muscle you get different colors. This is why sub surface scattering is all the rage, it lets you set up different layers and bounce light and colors around inside of those layers without having to model any of it. A good spec and defuse map combo can go a LONG way in faking the sub surface scattering look and helping to correct the horrible shadows some engines add with normal maps on the face. But you have to be almost hyper vigilant when making the spec map. You MUST pay attention to the layers of skin, muscle and know where the skin is thick, thin, age, health, blood flow. If you're just colorizing your spec map with blue you're missing the point of using a color map.
Not really, but I probably should have explained about the other attributes of a skin's specular map (intensity and the differences at certain areas) rather than a pretty general statement that lacked the proper qualifiers and explanation/correlary. It is indeed far more complex than a piece of fruit. So thank you for providing that and the detail I really should have provided (or better yet, not have mentioned skin, as you said). But as far as color specifically goes, what I said was generally correct. Skin's spec map should be pretty desaturated with some bluish-green (for caucasian skin at least, in all honesty I've never really done dark skins, though they tend to be more shiny, I can't comment how they differ). The reason is largely to provide a properly colored (or uncolored, as it were) highlight of something near white. My statement wasn't incorrect, nor was it specific or detailed enough to be considered correct or useful, it should just have been not said.
Anyway, skin's specular is definitely a topic for a different thread, sorry I brought it up. Any comment on plastic though?