correct terminology: shader maps? render maps? what are they called?

dorian

Hello Polycount!

I am a painter and illustrator, getting into 3D.

There are some concepts in 3D that are very helpful in 2D painting. One of them is the concept of "maps" like normal map, emissive map, specular map, diffuse map, etc.

What is the name of the category of these maps? There must be a more precise word than just "maps". Is it "Shader Maps"? Or "Render Maps"? Or something else? Or am I throwing different categories together here? As in normal maps being different from specular maps and those being different from texture maps again?

*confused*

hope you can help

Best,
Dorian

PS. just to not make this a text-only post, here's an image I did with ZBrush a while back:

Ace-Angel

Generally called Texture Maps.

-Color = Diffuse Map
-Shiny = Specularity Map
-Tightness of Shiny = Glossiness Map
-Glow = Emissive Map (or self illumination map)
-Transparency = Opacity Map (or opacity mask)
-Face information on a polygon = Normal Map (grey scale = bump map)
-Displacement = Height Map

cryrid

I imagine they could go by many names depending on the background of the artist or program being used, but generally you could probably just stick to calling them textures, maps, or texture maps and people will know what you're talking about.

Fake depth information with XYZ information = Normal Map

Isn't a normal map just overwriting the meshes' normals (the direction they'd be facing, not the depth)

Ace-Angel

cryrid wrote: »

I imagine they could go by many names depending on the background of the artist or program being used, but generally you could probably just stick to calling them textures and people will know what you're talking about.


Isn't a normal map just overwriting the meshes' normals (the direction they'd be facing, not the depth)

Gah, you're right, sorry.

Xoliul

cryrid wrote: »

Isn't a normal map just overwriting the meshes' normals (the direction they'd be facing, not the depth)

Not necessarily. That's only true for an Object-space normalmap. A Tangent space map (which is used much more and seen as the standard), doesn't overwrite but rather bends the normals relative to the already existing mesh normals.

equil

call them image files.

beyond the game industry (and even in it) the naming conventions are really haywire. nothing is really standard and unambiguous. you could easily call a gloss map a specular map and vice versa and it'd still be completely valid to a lot of people.

the wiki does an ok job at trying to categorize them.

Ace-Angel

equil wrote: »

call them image files.

beyond the game industry (and even in it) the naming conventions are really haywire. nothing is really standard and unambiguous. you could easily call a gloss map a specular map and vice versa and it'd still be completely valid to a lot of people.

the wiki does an ok job at trying to categorize them.

Gloss maps, sometimes, are called Specularity Power, which kinda makes sense, but a CGI artist will always have a basic training in Gloss, as the first term.

Which raises an interesting question from what you said, why doesn't the industry homogonize the lingo in mapping?

Xoliul

I think Treyarch even calls gloss maps "cosine maps" for some reason.

ZacD

Ace-Angel wrote: »

Gloss maps, sometimes, are called Specularity Power, which kinda makes sense, but a CGI artist will always have a basic training in Gloss, as the first term.

Which raises an interesting question from what you said, why doesn't the industry homogonize the lingo in mapping?

why don't we homogonize normal maps and xyz cord directions and scale?

equil

right, power because pow(spec,gloss), cosine because that's the technical term for the sampling method since nh=cosine of the angle between the light and half vectors.

standardizing would be nice, but it's pretty illogical how we use it. why is a glossy reflection the opposite of a high gloss reflection? i wish people would just call them roughness maps, would be both less ambiguous, more intuitive and has a tangible meaning.

cryrid

Xoliul wrote: »

Not necessarily. That's only true for an Object-space normalmap. A Tangent space map (which is used much more and seen as the standard), doesn't overwrite but rather bends the normals relative to the already existing mesh normals.

What I was getting at was that they were for the normals, not depth. 'Considering' probably would have been a better choice of words on my behalf.

Vailias

Equil: because roughness is a defined term in several shader models that functions differently than specular color or exponent.
.

equil

hmm, really? i can't think of any lighting model that uses roughness for something other than... well surface roughness. i'd be really glad if you could elaborate.

Vailias

In that respect you're right, and really my statement was probably more syntactic than semantic.

The exponentiation of the cosine term in the phong and blinn models *is* a quick and dirty way of simulating surface roughness and more diffused scattering.

I was thinking of the cook-torrence and oren-nayar models, which use roughness in a different way than a simple exponent, though the spirit of the different approaches is the same.

Sage

to be honest it would of been nice if the naming convention for real time shaders was exactly the same as in pre- rendered shaders so no confusion would exist. it would also be nice if all 3d graphics just used the same naming convention for texture maps.

shader is a material... a shader is a bit of code that takes image maps uses them to create the properties of a real life material...

properties of a shader would be

color - diffuse
spec -
gloss-
glow, emissive, self illumination
refection-
opacity, transperency
refraction
bump
displacement

ambershee

They're not all standardised because the implementation of the shader is what really defines what they are. 'Emissive' and 'Self-Illumination' as an example can be interpreted to be two different things (and are when I personally use them) - a self-illumination map is where the object can light itself, whereas an emissive map is where the object casts a light or glow from. In our engine, emissive maps are used to cast light into the scene, whereas a self-illumination map is used to light the object itself.

It's all entirely subjective though, because it's easy to apply different meanings down to the fact the implementation itself isn't standardised. Things like normal maps are pretty standardised, which is why everyone usually knows what you're tlaing about (although there are still discrepencies between coordinate systems, which is another example of implementation differing).

Ace-Angel

I always thought Emissive and Self Illumination where the same, since they're essentially 'controlled' by the user, and if they want it to glow or not.

Value = 1 is Self Illuminated while higher then 1 determines the Glow around the Self Illumination.

I personally would love Normals and Bi/Tangents be harmonized before anything.

ambershee

Terminology wise, self-illumination should be the light that the object is casting on itself. You'd probably treat that 'light' the same way you'd treat lighting from other sources when you collate it in the shader for the purposes of diffuse and specular calculations. It's illuminating itself.

Emissive maps are generally not handled as if they were a source of lighting and don't interact with the diffuse or specular in the same way, which is why they can be treated as a 'glow'. Lots of people use emissive maps to kind of do what I'm describing above though, especially in conjunction with a glowing source.


The trouble is that not everyone implements things this way

dorian

Thank you all for sharing your thoughts! I'm surprised that there doesn't seem to be just one term for this concept of maps.
Different material properties having different names in different engines makes sense though since the complexity of "recreating nature" makes for many ways of going about it..

Looks like we have:

Texture Maps - this seems confusing to me since there are "texture maps" used as parts of materials as well, correct?
Also, if "Texture Map" is the overall category, would you guys think of a "normal map" as being a "texture map"? To me it seems they are at the same level of hierarchy. That said... all these maps are textures, right? What a mess hehe

Shader Maps - I prefer this one I think. Any arguments against using that? A shader is code describing material properties, correct? Is it correct to say "shaders contain "maps"?"

Material Maps - never heard that one but it seems it would work as well. Is it practical to use "shader" and "material" as synonyms?

Render Maps - the maps are not as much about the rendering as about controlling material properties so this one can probably be neglected.

How about Material Property Maps? That is exactly what they are, right? Anything wrong with this term other than it being a bit clunky?


Anything to add?
Or subtract?
Thanks!

pior

As a whole, they are called texture maps ; individualy, "somethingmap" or "something map" (Diffuse texture/map, Normalmap, Specular map, and so on). Many of these terms are actually not very correct when you think of it (diffuse vs albedo...) but it all comes down to common usage. Just stick around here for about a week and you'll get the gist of it. Not much point in calling them differently just because you think it sounds better, thats for sure

And welcome!

dorian

Makes sense, thanks pior!

Definitely not looking for what sounds best Just if there is a commonly used term that includes all map types. I will be using this when I talk to people who are not familiar with 3D. I guess "Texture Maps" works and if I need to be more specific "Material Property Maps" can work, plus just giving examples of different maps.

Cheers!

edit: and nice & fun work on your site! Really looking forward to exploring all the talent here!