Chestnut's Multimedia Mania/MM_MANIA.ISO/graphics/povdoc2/textures.doc

Text File | 1993-08-05 | 17KB | 392 lines

                 Persistence of Vision Raytracer
            Standard Textures Include File Documentation

Textures are the materials that shapes and objects in POV-Ray are made
out of. It is possible to define almost infinite textures in POV-Ray
ranging from red marble, to pink alabaster, to shiny gold, to rippling
water.

The files TEXTURES.INC and STONES.INC contain many pre-defined textures
created by POV-Ray users. You can easily use these high-quality textures
in your own scene files by adding the lines,

   #include "colors.inc"
   #include "textures.inc"
or
   #include "colors.inc"
   #include "stones.inc"
or
   #include "colors.inc"
   #include "textures.inc"
   #include "stones.inc"

to the top of your scene file. Then, use the texture names described
below wherever you would normally place an entire texture definition.
For example,

   sphere { <0, 0, 0>, 1 texture { Texture_Name } }

or

   object {
       Logo
       texture { Texture_Name }
   }

These pre-defined textures may be scaled, translated, and rotated
like any other texture. For example,

   object {
       Logo
       texture {
         Texture_Name
         rotate -90*x   // rotate texture only
       }
       scale <5, 3, 2>  // scale shape and texture
   }


You may also modify them by placing texture parameters after the
Texture_Name. For example,

   object {
       Logo
       texture {
         Texture_Name
         pigment { agate }  // Use the agate color pattern instead.
         finish {
             phong 1        // Make the texture shiny
             reflection .5  // and reflective.
         }
       }
   }

You can easily create great looking scenes by invoking these pre-defined
textures with the shapes you create. Note that each texture definition
takes a bit of memory. If you are running out of memory, try copying the
individual textures out of these two files that you want to use instead
of including the entire file.

-------------------------------------------------------------------------

-What this document is, and what it is not:

This file is intended to be used as a quick reference to the textures
in the textures.inc file.  This won't tell you all you need to know about
any of these surfaces, but it should help you in picking what you want or
to look up the correct spelling of a name.  You will also find it valuable
to browse through the textures file from time to time.  There are a few
comments that aren't duplicated in this file.

This document is at times biased by my own preferences, but also by
considerable experimention and experience.  Nevertheless, don't take
anything I say in this text as pure, absolute fact.  Try things out
yourself and see what the result is.

After the quick reference, you'll find some handy tips on textures.

-R&D Dept:

You are strongly encouraged to develop your own custom version of these
textures, and to develop your own new surfaces.  Please share the nice ones
with the folks that are sharing this with you.  Who knows... it might be
in the next release.  Oh... if you share a file with someone, please make
sure that any custom textures, colors, or shapes are included.  Saves lots
of frustration on the recipient.

There are a number of textures in here that could be improved on.  Please
don't take anything in the textures files for "gospel".  Everything can
be improved upon.  Manipulate turbulence, octaves.  Try Jade using granite
instead of marble.

-About the textures file:
These textures have generally been scaled to fit best onto a "unit" object,
for example, on a sphere with radius of 1.  Rescale accordingly.  Remember,
scaling larger puts less of the texture *features*  into a given area.

Note: You MUST include colors.inc BEFORE textures.inc.  Many of these
textures use declared color names and POV-Ray won't like it if they haven't
been defined when it's parsing the textures!

    - Dan Farmer



-Textures file #1, contents, with comments.

Stone Textures      My personal opinions, for what it's worth.  -dmf
--------------
Jade           Swirled jade.  Try with agate, too!
Red_Marble     A bit overworked and unrealistic, but a classic.
White_Marble   Nice for an underlying texture with another marble, too.
Blood_Marble   Does this one really need a description? You'll try it, anyway!
Blue_Agate     Another classic.  Kind of blue-gray or purplish.
Sapphire_Agate Very nice, velvety dark blue stone.
Brown_Agate    Pretty tawny brown on white.
Pink_Granite   Black, white, and orange granite.
Pink_Alabaster Soft gray/rose alabaster. Subtle and beautiful!

Sky Textures  - Manipulate the scale and the turbulence for best results.
-----------
Blue_Sky         Your basic blue sky, with clouds.
Blue_Sky2        Variation on basic blue sky, with clouds.
Blue_Sky3        Variation on basic blue sky, with small puffy clouds.
Bright_Blue_Sky  Bright blue sky with whiter-than-white clouds.
Blood_Sky        Drastic red sky with stormy yellow clouds.  Surrealistic.
Apocolypse       Black sky with red and purple clouds.  Another CdW dreamscape.
Clouds           Clouds with a clear sky.  Generally has a blue sphere behind.

Wooden Textures - Again, try manipulating scale, translation, and turbulence.
---------------

Cherry_Wood      A light reddish wood.
Pine_Wood        Light tan wood with greenish growth rings.
Dark_Wood        Dark wood with a greenish hue to it.
Tan_Wood         Light tan background with brown rings.
White_Wood       A very pale wood with tan rings -- kind of balsa-ish.
Tom_Wood         Brown wood - looks stained.

Dan Farmer woods
DMFWood1         Kind of like cedar, maybe?
DMFWood2         Light colored wood.
DMFWood3         Rosewood, very pretty red/black.
DMFWood4         Another light, piney wood.
DMFWood5         Grayish-tan.
DMFLightOak      A very realistic looking fresh white oak surface.
DMFDarkOak       Similar to DMFLightOak, but with a typical oak stain.
Cork             A very realistic looking cork texture

Doug Otwell woods
Yellow_Pine       A beautiful yellow pine.
Rosewood          Deep red/black woodgrain.
Sandalwood        Highly turbulated creamy-gray.  Great burled maple, too!

Surface Textures
----------------
Dull             We all know somebody like this guy, don't we? Uses specular.
Shiny            Small, tight highlights.  No reflection.      Uses specular.
Phong_Dull       Like a soft rubber ball or flat paint.
Phong_Shiny      Some say that phong is less worthy than specular. I use this.
Glossy           Shinier than shiny.  Has some reflection included.
Phong_Glossy     Similar to Glossy, but uses phong.  Very tight highlight.
Luminous         Good for sky-spheres, no shadows will be cast on it.
Mirror           A perfect mirror.  The raytraced sphere classic.
Glass            Clear glass.  May want to add Gloss.
Glass2           Probably more like acrylic plastic. Softer gloss that glass.
Glass3           An excellent grayish lead crystal. New with POV-Ray 1.0.
Green_Glass      Glass3 with a pale green tint to it.

Metal Textures
--------------
Metal           Add your own color before using this one.

                The following textures are referred to by two names,
                one (hopefully) for historic purposes only.  I wanted to
                use simple "Brass" and "Silver" but it interferes with the
                colors of the same names.

Chrome_Metal     (preferred name)      Chrome_Texture  (historical name)
Brass_Metal      (preferred name)      Brass_Texture   (historical name)
Gold_Metal       (preferred name)      Gold_Texture    (historical name)
Bronze_Metal     (preferred name)      Bronze_Texture  (historical name)
Copper_Metal     (preferred name)      Copper_Texture  (historical name)
Silver_Metal     (preferred name)      Silver_Texture  (historical name)

Polished_Chrome  A highly reflective chrome texture
Polished_Brass   A highly reflective brass texture
New_Brass        Beautiful military brass texture
Spun_Brass       Spun Brass texture for cymbals & such

Brass_Valley    Hmmmm... something like "Black Hills Gold".
Rusty_Iron      Just like my car.
Rust            Just like my car's finish.

Special Effect Dept
-------------------
Candy_Cane      Red and white barber pole.
Peel            Orange and transparent spiral stripes. Use it to emulate
                the artist M.C. Escher.
X_Gradient      Here as an example more than as a useful texture
Y_Gradient      Here as an example more than as a useful texture
Z_Gradient      Here as an example more than as a useful texture
Water           Requires a sub-surface.  Has transparency and ripples.

Texture from stones.inc:

           This file contains #Declared texture statements defining a variety
           of Granite & Marble Textures. Most use the Granite Texture.
           Turbulence has no effect on Granite, but turbulence is stated
           before the Color Map for convenience of switching to Marble, which
           does need a turbulence to swirl the color. I tried to avoid using
           a random Dither, but I find it helps create a subtle grain & can
           spark lost colors in the map. On multi-layered texture, try a float
           of about 0.05 on the first texture. -- Mike Miller

        INDEX:
        GRNT0  - GRNT20   color maps containing no alpha values
            grnt0  - Gray with Rose
            grnt1  - Creamy Whites with yellow & light gray
            grnt2  - Deep Cream with light rose orchid & tan
            grnt3  - Warm tans olive & light rose with cream
            grnt4  - Orchid sand & mauve
            grnt5  - Medium Mauve Med.Rose & deep cream
            grnt6  - Med. Orchid Olive & Dark Tan "mud pie"
            grnt7  - Dark Orchid Olive & Dark Putty
            grnt8  - Rose & Light cream Yellows
            grnt9  - Light Steely Grays
            grnt10 - Gray Creams & lavender tans
            grnt11 - Creams & Grays
            grnt12 - Tan Cream & Red Rose
            grnt13 - Cream Rose orange
            grnt14 - Cream Rose & light moss
            grnt15 - Black with subtle chroma
            grnt16 - White Cream & Peach
            grnt17 - Bug Juice & Green
            grnt18 - ??
            grnt19 - ??   (This one does have some transparency-dmf)
            grnt20 - Gray Marble with White feather Viens

        GRNT0A - GRNT20A  color maps containing alpha
            grnt0a -grnt7a- ???
            grnt8a  - Aqua Tints
            grnt9a  - Alpha Creams With Cracks
            grnt10a - Alpha Cream Rose & light yellow
            grnt11a - Alpha Light Grays
            grnt12a - Alpha Creams & Tans
            grnt13a - Alpha Creams & Grays
            grnt14a - Cream Rose & light moss
            grnt15a - Alpha Sand & light Orange
            grnt16a - Cream Rose & light moss (again?)
            grnt17a - ???
            grnt18a - ???
            grnt19a - Gray Marble with White feather Viens with Alpha
            grnt20a - Black/Gray Marble

        CRACK1 & CRACK2   clear with an thin opaque band for cracks
            crack1 - Crack & Red Overtint
            crack2 - Translucent Dark Cracks

        OTHERS
            marb3 - Warm tans & light rose with cream (opaque)
            marb9 - Light Grays (opaque)

        STONE1 - STONE16  complete texture statements - edit to your
                          scene & lighting situations.

            stone1 - LightCream
            stone2 - Cream & sand
            stone3 - Cream Stone with warm swirls
            stone4 - Cream Stone with larger warm swirls
            stone5 - Cream Stone with warm swirls
            stone6 - Cream Stone with warm swirls
            stone7 - Cream Stone with warm swirls
            stone8 - Cream Stone with warm swirls
            stone9 - Cream Stone with warm swirls
            stone10- Cream Stone with warm swirls
            stone11- Cream Stone with warm swirls
            stone12- Light Cream
            stone13- Light Cream
            stone14- Light Cream
            stone15- Light Cream
            stone16- Light Cream

           Final Note: I would not "INCLUDE" this whole data file into a scene
                       file if only one or two of these textures were being
                       used...There are too many declares being used.
                      - Mike Miller


------------------------- OTHER STUFF -------------------------------------

                     STONE TEXTURES

I think you will find that in most cases, to put a marble or to a
lesser degree, agate, texture onto an x/z plane, you will get the best
results by rotating the final texture by <0, 0, 90>.  This will give a
less directional noise to the marbling.

Don't overlook the granite texture.  You can do a lot more than granite
with it by changing colors, scale, and turbulence.

The onion texture makes a superb marblized surface if you give it enough
turbulence, and it lacks the  directional quality of the built-in
marble.  This is essentially the same texture as the "spherical" texture in
the Vivid raytracer and can be used in much the same ways.

The file "stones.inc" contains a number of other stone textures, these by
POV-Ray artist Mike Miller.  Be sure to check these out... they'll "blow your
socks off"!


                          WOODEN TEXTURES

Note:  Wood is designed like a "log", with growth rings aligned along
the z axis.  Generally these will look best when scaled down by about
a tenth (to a unit-sized object).  You may want to try using a smaller
value for the turbulence with these textures, too (try around 0.05
for starters).

The scaling in these definitions is relative to a unit-sized object
(radius 1).  Note that woods are functionally equivilent to a log lying
along the z axis.  For best results, think like a woodcutter trying to
extract the nicest board out of a log.  A little tilt along the x axis
will give elliptical rings of grain like you'd expect to find on most boards.
Experiment.


                     SURFACE TEXTURES

Glass and mirrors are tough things to render, although at the same time,
they are the forte of raytracing.  The reason I say that they are tough is
that the effect is stronly dependant upon the environment.  Look closely at
a glass or bottle or a piece of silverware and you'll see what I mean.  The
color of the object comes primarily from the surroundings, and very little
from the object itself.

The mirror defined in the textures file is a "perfect" mirror.  You won't even
find that in Sandia Labs laser lab.  But, hey... raytracing isn't reality, is
it?  Still, if you're trying to model glass or mirror with the intent of
modelling "reality",  you will probably want to add a touch of diffuse
color to the texture and manipulate some of the other values until you get
what you're looking for.  Discovery is half the fun!
Oh... sometimes a touch of "brilliance" will look good on mirror and glass,
too.


                          OTHER THOUGHTS

As you use these textures,  remember that you can "borrow" one of these
textures and modify it by either adding other qualities, or by changing
qualities that are declared in the definition.  For example,

    pigment {
        Jade                   // Use Jade coloring
        onion                  // Use onion pattern instead of marble
        turbulence 0.7         // "Over-write" Jade's high turbulence
    }

The best way to learn about any given texture is simply to take some time
and play with it.  The first thing I would recommend is to map it onto
a unit object.  Set turbulence to 0.  Use default scaling.

For the following textures, I'd recommend these shapes:

    wood      object { Z_Disk }.
    marble    object { UnitBox }.
    agate     object { UnitBox }.
    onion     cut a sphere in half with CSG.  Flat side facing camera.
    leopard   sphere.
    granite   just about anything.
    checker   object { UnitBox }.
    bozo      just about anything.



You can achieve some spectacular results by layering textures, but it can
also get frustrating sometimes.  The method is generally to use a color map
on the top surfaces that has some sort of a blend between a color and clear
white.  As the color and the clear blend together, you will get varying
degrees of "semi-clear" white that will modify the underlying color in ways
that you may not have planned on.  Once again, experiment.