Using colour in your specular maps

[soulburn3d]

Well, it really depends what you're going for. In the real world, specularity is based on the material. Non metals like plastic do not tint the specular reflection, so the specular is the color of the actual reflection. Metals do tint the reflection, so for example a specular on gold will be golden colored. If you don't care about reality and are more interested in making something painterly, then whatever you want goes, but it's good to note that if your specular is the same color as your object, the eye may mistake the material for a metal because we're so used to seeing that in the real world.

- Neil

[Metafiction]

Thanks Neil.

Are their any sources you would recommend for further reading and insight into real life materials/shaders(mentalray or otherwise)? Or is your advice bourne of years of observation and personal research?


I read some of the more technical papers on things like BRDF in the past, but I am not afraid to admit some of it is way above my head. Anything that might help my approach to materials would be of help though.

I'd just like to say your in depth shader tutorials (and many others)have been of great help in the past, primarily because of this kind of invaluable insight into the "whys and wherefores", so again, thanks.

[soulburn3d]

Glad you've found my tutorials useful. My information comes from a number of sources, an old siggraph course from 1996 about color and light ranks highly in my book, but a lot of it is from personal experience and observation. Actually, one thing that's really missing in all the books out there is a good shading book. Not shading like "here's how to program a shader", and not "here's how to use photoshop to paint a texture", but an honest to god shading book about different materials and what makes a material look the way it does, and how to replicate it in cg. Maybe I'll have to write one eventually.

- Neil

[Metafiction]

Yeah, I'm positive such a guide to real world materials (and even lighting or lens effects) would be invaluable, as most books/dvds/tutorials focus solely on program specific technical aspects, as opposed to the more basic questions that allow you to replicate the effect.

There will always be a need to "bootstrap" yourself and look at what is actually happening around you, and often areas like this can be harder to write about as they rely upon more abstract/subjective concepts(like composition or form) that take years to truly understand, but I think theres a niche for general tips and observations from senior artists.

I've always been greatful when a supervisor has pointed something out that has taken them years of trial and error. It effectively gives a "short-cut" you can confidently use in production whilst offering insight into something you can test out the reasoning for in your own time.


If you write it they will come.

Thanks.

[gregsandor]

Goethe's Theory of Color ought to be on everyone's bookshelf. This was written long before computer graphics existed, but what we do today isn't much different than when we used paint and brush.

[EricChadwick]

Oooh, I want to read this, thank you.

Niklas Jansson's paper might also be interesting to you.
http://itchstudios.com/psg/art_tut.htm

Also Richard Harris' paper.
http://www.itchy-animation.co.uk/tutorials/light01.htm

[Metafiction]

Thankyou for your suggestions and links.

I actually had one of Niklas Jansson's radiosity images but didn't know he had a more comprehensive page. Great stuff.

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.