Difference between revisions of "Reference:Pattern"
Jholsenback (talk | contribs) m (link correction) |
Jholsenback (talk | contribs) m (moved some sub-sections to separate files) |
||
Line 1: | Line 1: | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
{{#indexentry:pattern modifiers}} | {{#indexentry:pattern modifiers}} | ||
− | |||
==Pattern Modifiers== | ==Pattern Modifiers== | ||
<p>Pattern modifiers are statements or parameters which modify how a pattern | <p>Pattern modifiers are statements or parameters which modify how a pattern | ||
Line 292: | Line 219: | ||
<li><code>noise_generator 3</code> generates Perlin noise</li> | <li><code>noise_generator 3</code> generates Perlin noise</li> | ||
</ul> | </ul> | ||
− | |||
− |
Revision as of 22:09, 18 July 2012
Pattern Modifiers
Pattern modifiers are statements or parameters which modify how a pattern is evaluated or tells what to do with the pattern. The complete syntax is:
PATTERN_MODIFIER: BLEND_MAP_MODIFIER | AGATE_MODIFIER | DENSITY_FILE_MODIFIER | QUILTED_MODIFIER | BRICK_MODIFIER | SLOPE_MODIFIER | noise_generator Number| turbulence <Amount> | octaves Count | omega Amount | lambda Amount | warp { [WARP_ITEMS...] } | TRANSFORMATION BLEND_MAP_MODIFIER: frequency Amount | phase Amount | ramp_wave | triangle_wave | sine_wave | scallop_wave | cubic_wave | poly_wave [Exponent] AGATE_MODIFIER: agate_turb Value BRICK_MODIFIER: brick_size Size | mortar Size DENSITY_FILE_MODIFIER: interpolate Type SLOPE_MODIFIERS: <Altitude> <Lo_slope,Hi_slope> <Lo_alt,Hi_alt> QUILTED_MODIFIER: control0 Value | control1 Value PIGMENT_MODIFIER: PATTERN_MODIFIER | COLOR_LIST | PIGMENT_LIST | color_map { COLOR_MAP_BODY } | colour_map { COLOR_MAP_BODY } | pigment_map{ PIGMENT_MAP_BODY } | quick_color COLOR | quick_colour COLOR COLOR NORMAL_MODIFIER: PATTERN_MODIFIER | NORMAL_LIST | normal_map { NORMAL_MAP_BODY } | slope_map{ SLOPE_MAP_BODY } | bump_size Amount TEXTURE_PATTERN_MODIFIER: PATTERN_MODIFIER | TEXTURE_LIST | texture_map{ TEXTURE_MAP_BODY } DENSITY_MODIFIER: PATTERN_MODIFIER | DENSITY_LIST | COLOR_LIST | color_map { COLOR_MAP_BODY } | colour_map { COLOR_MAP_BODY } | density_map { DENSITY_MAP_BODY }
Default values for pattern modifiers:
dist_exp : 0 falloff : 2.0 frequency : 1.0 lambda : 2.0 major_radius : 1 map_type : 0 noise_generator : 2 octaves : 6 omega : 0.5 orientation : <0,0,1> phase : 0.0 poly_wave : 1.0 strength : 1.0 turbulence : <0,0,0>
The modifiers PIGMENT_LIST, quick_color
, and pigment_map
apply only to pigments. See the section Pigment for details on these pigment-specific pattern modifiers.
The modifiers COLOR_LIST and color_map
apply only to pigments and densities. See the sections Pigment and Density for details on these pigment-specific pattern modifiers.
The modifiers NORMAL_LIST, bump_size
, slope_map
and normal_map
apply only to normals. See the section Normal for details on these normal-specific pattern
modifiers.
The TEXTURE_LIST and texture_map
modifiers can only be used with patterned textures. See the section Texture Maps for details.
The DENSITY_LIST and density_map
modifiers only work with media{density{..}}
statements. See the section Density for details.
The agate_turb
modifier can only be used with the agate
pattern. See the section Agate for details.
The brick_size
and mortar
modifiers can only be used with the brick
pattern. See the section Brick for details.
The control0
and control1
modifiers can only be used with the quilted
pattern. See the section Quilted for details.
The interpolate
modifier can only be used with the density_file
pattern. See the section Density File for details.
The general purpose pattern modifiers in the following sections can be used with pigment
, normal
, texture
, or density
patterns.
Transforming Patterns
The most common pattern modifiers are the transformation modifiers translate
, rotate
, scale
, transform
, and matrix
. For details on these commands see the section Transformations.
These modifiers may be placed inside pigment, normal, texture, and density statements to change the position, size and orientation of the patterns.
Transformations are performed in the order in which you specify them.
However in general the order of transformations relative to other pattern
modifiers such as turbulence
, color_map
and other
maps is not important. For example scaling before or after turbulence makes
no difference. The turbulence is done first, then the scaling regardless of
which is specified first. However the order in which transformations are
performed relative to warp
statements is important. See the section Warps for details.
Frequency and Phase
The frequency
and phase
modifiers act as a type
of scale and translate modifiers for various blend maps. They only have
effect when blend maps are used. Blend maps are color_map
,
pigment_map
, normal_map
, slope_map
,
density_map
, and texture_map
. This discussion uses
a color map as an example but the same principles apply to the other blend
map types.
The frequency
keyword adjusts the number of times that a color
map repeats over one cycle of a pattern. For example gradient
covers color map values 0 to 1 over the range from x=0 to x=1. By adding frequency 2.0
the color map repeats twice over that same range. The same effect can be achieved using scale 0.5*x
so the frequency keyword is not that useful for patterns like gradient.
However the radial pattern wraps the color map around the +y-axis once. If
you wanted two copies of the map (or 3 or 10 or 100) you would have to build
a bigger map. Adding frequency 2.0
causes the color map to be
used twice per revolution. Try this:
pigment { radial color_map{ [0.5 color Red] [0.5 color White] } frequency 6 }
The result is six sets of red and white radial stripes evenly spaced around the object.
The float after frequency
can be any value. Values greater than
1.0 causes more than one copy of the map to be used. Values from 0.0 to 1.0
cause a fraction of the map to be used. Negative values reverses the map.
The phase
value causes the map entries to be shifted so that the map starts and ends at a different place. In the example above if you render successive frames at phase 0
then phase 0.1
, phase 0.2
, etc. you could create an animation that rotates the stripes. The same effect can be easily achieved by rotating the radial
pigment using rotate y*Angle
but there are other uses where phase can be handy.
Sometimes you create a great looking gradient or wood color map but you want
the grain slightly adjusted in or out. You could re-order the color map
entries but that is a pain. A phase adjustment will shift everything but
keep the same scale. Try animating a mandel
pigment for a color
palette rotation effect.
These values work by applying the following formula
New_Value = fmod ( Old_Value * Frequency + Phase, 1.0 ).
The frequency
and phase
modifiers have no effect on block patterns checker
, brick
, and hexagon
nor do they effect image_map
, bump_map
or material_map
. They also have no effect in normal statements when used with bumps
, dents
, quilted
or wrinkles
because these normal patterns cannot use normal_map
or slope_map
.
They can be used with normal patterns ripples
and waves
even though these two patterns cannot use normal_map
or slope_map
either. When used with ripples
or waves
, frequency
adjusts the space between features and phase
can be adjusted from 0.0 to 1.0 to cause the ripples or waves to move relative to their center for animating the features.
Waveforms
POV-Ray allows you to apply various wave forms to the pattern function
before applying it to a blend map. Blend maps are color_map
,
pigment_map
, normal_map
, slope_map
,
density_map
, and texture_map
.
Most of the patterns which use a blend map, use the entries in the map in
order from 0.0 to 1.0. The effect can most easily be seen when these patterns
are used as normal patterns with no maps. Patterns such as
gradient
or onion
generate a groove or slot that looks
like a ramp that drops off sharply. This is called a ramp_wave
wave type and it is the default wave type for most patterns. However the
wood
and marble
patterns use the map from 0.0 to
1.0 and then reverses it and runs it from 1.0 to 0.0. The result is a wave
form which slopes upwards to a peak, then slopes down again in a
triangle_wave
. In earlier versions of POV-Ray there was no way to
change the wave types. You could simulate a triangle wave on a ramp wave
pattern by duplicating the map entries in reverse, however there was no way
to use a ramp wave on wood or marble.
Now any pattern that takes a map can have the default wave type overridden. For example:
pigment { wood color_map { MyMap } ramp_wave }
Also available are sine_wave
, scallop_wave
,
cubic_wave
and poly_wave
types. These types are of
most use in normal patterns as a type of built-in slope map. The
sine_wave
takes the zig-zag of a ramp wave and turns it into a gentle
rolling wave with smooth transitions. The scallop_wave
uses the
absolute value of the sine wave which looks like corduroy when scaled small
or like a stack of cylinders when scaled larger. The cubic_wave
is a gentle cubic curve from 0.0 to 1.0 with zero slope at the start and end.
The poly_wave
is an exponential function. It is followed by an
optional float value which specifies exponent. For example poly_wave
2
starts low and climbs rapidly at the end while poly_wave
0.5
climbs rapidly at first and levels off at the end. If no float
value is specified, the default is 1.0 which produces a linear function
identical to ramp_wave
.
Although any of these wave types can be used for pigments, normals, textures, or density the effect of many of the wave types are not as noticeable on pigments, textures, or density as they are for normals.
Wave type modifiers have no effect on block patterns checker
,
brick
, object
and hexagon
nor do they effect
image_map
, bump_map
or material_map
. They
also have no effect in normal statements when used with bumps
,
dents
, quilted
, ripples
,
waves
, or wrinkles
because these normal patterns cannot
use normal_map
or slope_map
.
Noise Generators
There are three noise generators implemented. Changing the noise_generator
will change
the appearance of noise based patterns, like bozo and granite.
noise_generator 1
the noise that was used in POV_Ray 3.1noise_generator 2
range corrected version of the old noise, it does not show the plateaus seen withnoise_generator 1
noise_generator 3
generates Perlin noise