Textures / Shading etc. - Losing the will to live :)

[Jozvex]

Hi there! Just take a deeeep breath.... it can be confusing at first especially when you try out multiple programs because their lingo can be slightly different too.

A shader is something that grants the overall surface properties of an object. For example, a Lambert shader allows you to control the object diffusely, with no reflection/refraction/shininess type properties. You might use a Lambert to create rocks or chalk etc. If your object needs to be reflective or shiny, you could use a Phong or Blinn shader.

The shader is the basic starting point to work off. Other programs like 3DS Max use the term material instead of shader.

A texture is a 2D/3D image (procedural or hand made) that can be used to control just about any of a shader's properties in more detail. Usually you would refer to the two types as either a Texture Map or Procedural Texture. In Maya a lot of people call texture maps File Textures too, because you use a File Texture node to load the image.

A Bump Map for example, could be either 2D, 3D, procedural or hand painted. You just use whatever you want in order to create the bumpiness of your shader.

As for procedural vs painted, it's just whatever you feel works best for that particular property of that particular shader. If I make a 3D T-shirt model, I'd probably hand paint (or use a photo or whatever) the logo on the front, but I'd use a procedural to create the actual fibers of the shirt. No-ones going to hand paint all the fibres on a shirt unless they need something really weird (or they're just plain crazy).

Just play around in Maya more and you'll get used to it all. Leigh (an administrator/super texture girl) wrote quite a few articles on texturing ages ago, here's her website:

http://leigh.cgcommunity.com/tutorials.htm

You should check it out!

:thumbsup:

[mixermanic]

Thank you!

A shader is something that grants the overall surface properties of an object. For example, a Lambert...
<snip>
...you could use a Phong or Blinn shader.


Aha! - so in simplified language, you *always* use a shader, a texture/diffusion/displacement/bump map can be regarded as one or more of the properties of that shader...? (thinking aloud here :) )

Are Lambert, Phong, and Blinn the only shaders?


A Bump Map for example, could be either 2D, 3D, procedural or hand painted.


A bump map can be 3D? Is that not a displacement map? If you use a 3D bump map does it affect the geometry at rendertime (as a disp map would) or just the shader?

Leigh (an administrator/super texture girl) wrote quite a few articles on texturing ages ago

Downloaded 'em. I should be sleeping (it's half 6! :argh: ) but sod it...! :)

Thanks for the reply!! The fog is lifting... :lightbulb

[Jozvex]

Aha! - so in simplified language, you *always* use a shader, a texture/diffusion/displacement/bump map can be regarded as one or more of the properties of that shader...? (thinking aloud here :) )

Yes, exactly!

Are Lambert, Phong, and Blinn the only shaders?

Definitely not. Those three I would say are the most common across all 3D packages. The thing with shaders is, that you could create exactly the same end result with a lot of them, it's just that each is slighty (or greatly) more tailored to certain kinds of surface types. You could more or less design an "Uber Fantastico of Greatness" shader, that can do any sort of surface property imagineable, but then it'd be so complicated and have so many options on it it'd be stupid. You might just want to create a plain red sphere and then at rendertime you'd be calculating all 5 million of the properties when you only needed 2. That's why there are lots of different shaders to choose from. They usually have different shading algorithms too.

When it comes to renderers like Renderman and Mental Ray, users that know what they're doing can design their own shaders too. There are starting to be LOTS of Mental Ray shaders around the internet now that have been created by talented shader writers. The shaders can do anything from cartoon effects, realistic skin, to glowy-magicy-stuff (technical term there) etc.

A bump map can be 3D? Is that not a displacement map? If you use a 3D bump map does it affect the geometry at rendertime (as a disp map would) or just the shader?

Well, no the object isn't affected like a displacement map. A bump map can "be 3D" if you use a 3D procedural texture. Procedurals that are 3D are kinda like.......a hologram? (bear with me people, haha). Imagine if......the room was full of floating holographic spheres. If you walked into the middle of them, you'd be intersecting them all over your body's surface. A 3D procedural basically does that, it's a volume of polkadots/wiggles/random-noise and wherever your model is intersecting with the volume, it gets those colours from it.

Yeah........that was probably the weirdest thing I've ever said. Just pretend I know what I'm talking about!!

Thanks for the reply!! The fog is lifting... :lightbulb

Don't worry, 3D is a very foggy place and people kinda just bob in and out of it along the way.

:scream:

[Splin]

Are there any good books out there regarding this?

Here you go, gives you good general basic information about different techniques/terms etc:
http://www.amazon.com/exec/obidos/tg/detail/-/1562059548/qid=1124100571/sr=8-1/ref=pd_bbs_1/102-9643406-9464150?v=glance&s=books&n=507846

[mixermanic]

Thanks Splin! Got the book on order now.

Definitely not. Those three I would say are the most common across all 3D packages. The thing with shaders is, that you could create exactly the same end result with a lot of them, it's just that each is slighty (or greatly) more tailored to certain kinds of surface types.

I'll have a look around and probably get back to you with another 100 questions :D

Imagine if......the room was full of floating holographic spheres.

I'm lighting the spliff as I read this :buttrock:

I think I follow. Will give it a go in Maya and see how spaced out I get :)

Thanks!!

Martin

[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.