Color, effects and textures

Every example on this page runs after these two lines, and ends by sending a color to the Output node:

from pyzed import shading

g = shading.Graph("demo")

Color

Colors are vec3 (r, g, b) or vec4 (r, g, b, a) with values from 0 to 1, not from 0 to 255: (1, 0.5, 0) is orange.

HSV to RGB

hsv_to_rgb · Color · g.hsv_to_rgb(...)

A color from hue (0 to 1 around the wheel), saturation and value.

A color from hue (0..1 around the color wheel: red, yellow, green, cyan, blue, magenta, red), saturation and value. Wire Time into the hue for a rainbow that cycles.

Input	Type	Default
h · hue	float	0
s · saturation	float	1
v · value	float	1

Output	Type
rgb	vec3

Example

uv = g.uv()
g.output(g.rgba(g.hsv_to_rgb(uv["x"], 0.8, 1.0), 1.0))

RGB to HSV

rgb_to_hsv · Color · g.rgb_to_hsv(...)

The hue, saturation and value of a color.

Splits a color into hue, saturation and value, to change one of them.

Input	Type	Default
rgb	vec3	(1, 0, 0)

Output	Type
hsv	vec3
h · hue	float
s · saturation	float
v · value	float

Example

hsv = g.rgb_to_hsv([1.0, 0.5, 0.0])
g.output(g.rgba(g.hsv_to_rgb(hsv["h"], 0.3, hsv["v"]), 1.0))

Hue shift

hue_shift · Color · g.hue_shift(...)

Turns the hue of a color (shift from 0 to 1 is a full turn).

Turns the hue of a color around the wheel (shift 1 is a full turn).

Input	Type	Default
rgb	vec3	(1, 0, 0)
shift	float	0.25

Output	Type
rgb	vec3

Example

g.output(g.rgba(g.hue_shift([1.0, 0.2, 0.2], g.time(scale=0.2)["time"]), 1.0))

Saturation

saturation · Color · g.saturation(...)

More (above 1) or less (below 1) colorful; 0 is gray.

More (above 1) or less (below 1) colorful; 0 is gray.

Input	Type	Default
rgb	vec3	(1, 0.5, 0)
amount	float	1.5

Output	Type
rgb	vec3

Example

c = g.palette(g.uv()["x"])
g.output(g.rgba(g.saturation(c, 0.4), 1.0))

Brightness and contrast

brightness_contrast · Color · g.brightness_contrast(...)

Lighter or darker, and more or less contrast.

Lighter or darker, and more or less contrast, like a photo editor.

Input	Type	Default
rgb	vec3	(0.5, 0.5, 0.5)
brightness	float	0
contrast	float	1

Output	Type
rgb	vec3

Example

c = g.palette(g.uv()["x"])
g.output(g.rgba(g.brightness_contrast(c, 0.1, 1.4), 1.0))

Luminance

luminance · Color · g.luminance(...)

How bright a color looks, from 0 to 1.

How bright a color looks to the eye, as one number from 0 to 1.

Input	Type	Default
rgb	vec3	(1, 1, 1)

Output	Type
value	float

Example

l = g.luminance([0.2, 0.7, 0.3])
g.output(g.rgba(l, 1.0))

Grayscale

grayscale · Color · g.grayscale(...)

The color in shades of gray.

The color in shades of gray (black and white).

Input	Type	Default
rgb	vec3	(1, 0.5, 0)

Output	Type
rgb	vec3

Example

c = g.palette(g.uv()["x"])
g.output(g.rgba(g.grayscale(c), 1.0))

Invert

invert · Color · g.invert(...)

The opposite color: 1 − color (alpha is kept).

The negative of a color (1 − color); alpha is kept.

Input	Type	Default
color	T	(1, 0.5, 0)

Output	Type
color	T

Example

c = g.gradient(g.uv()["x"])
g.output(g.invert(c["color"]))

Gamma

gamma · Color · g.gamma(...)

Brightens (above 1) or darkens (below 1) the midtones.

Brightens (above 1) or darkens (below 1) the midtones without touching black and white.

Input	Type	Default
rgb	vec3	(0.5, 0.5, 0.5)
gamma	float	2.2

Output	Type
rgb	vec3

Example

v = g.uv()["x"]
g.output(g.rgba(g.gamma(g.compose(v, v, v), 2.2), 1.0))

Posterize

posterize · Color · g.posterize(...)

Keeps only a few steps of each component.

Keeps only a few steps of each color: cel shading and retro looks.

Input	Type	Default
color	T	(0.3, 0.6, 0.9)
steps	float	4

Output	Type
color	T

Example

c = g.palette(g.uv()["x"])
g.output(g.rgba(g.posterize(c, 4.0), 1.0))

Blend

blend · Color · g.blend(...)

Blends layer over base like an image editor’s layer modes.

Blends layer over base like the layer modes of an image editor: normal, multiply, screen, overlay, add, subtract, difference, darken, lighten, soft light, color dodge and color burn.

Input	Type	Default
base	vec3	(0.2, 0.4, 0.8)
layer	vec3	(1, 0.6, 0.2)
opacity	float	1

Output	Type
rgb	vec3

Setting	Values	Default
mode	normal, multiply, screen, overlay, add, subtract, difference, darken, lighten, soft_light, color_dodge, color_burn	multiply

Example

base = g.gradient(g.uv()["y"])
clouds = g.fbm(scale=3.0)
layer = g.compose(clouds, clouds, clouds)
g.output(g.rgba(g.blend(base["rgb"], layer, 0.8, mode="screen"), 1.0))

Palette

palette · Color · g.palette(...)

A smooth rainbow-like color for t, from Inigo Quilez’s cosine palettes: a + b × cos(2π(c × t + d)).

Turns a number from 0 to 1 into a smooth, rainbow-like color with a cosine formula. Change d to shift the colors; it is the quickest way to color noise.

Input	Type	Default
t	float	0
a	vec3	(0.5, 0.5, 0.5)
b	vec3	(0.5, 0.5, 0.5)
c	vec3	(1, 1, 1)
d	vec3	(0, 0.33, 0.67)

Output	Type
rgb	vec3

Example

n = g.noise(scale=4.0)
g.output(g.rgba(g.palette(n), 1.0))

Gradient

gradient · Color · g.gradient(...)

A color ramp: the color at t (0 to 1) between the stops you set.

A color ramp you edit with stops: the color at t between the stops. In the designer you drag the stops; in Python pass stops=[[position, color], ...].

Input	Type	Default
t	float	0.5

Output	Type
color	vec4
rgb	vec3
alpha	float

Setting	Values	Default
stops	stops	0 #1e1b4b, 0.5 #db2777, 1 #fde047

Example

ramp = g.gradient(g.uv()["x"], stops=[[0.0, "#0f172a"], [0.6, "#7c3aed"], [1.0, "#f472b6"]])
g.output(ramp)

RGBA

rgba · Color · g.rgba(...)

A color with alpha from a vec3 color and an opacity.

Joins an RGB color and an opacity into the vec4 the Output wants.

Input	Type	Default
rgb	vec3	(1, 1, 1)
alpha	float	1

Output	Type
color	vec4

Example

g.output(g.rgba([0.2, 0.6, 1.0], 0.5))

Layer

layer · Color · g.layer(...)

Puts front over back using front’s alpha.

Puts front over back using front’s alpha, like stacking two layers.

Input	Type	Default
back	vec4	(0, 0, 0, 1)
front	vec4	(1, 1, 1, 0.5)

Output	Type
color	vec4

Example

back = g.gradient(g.uv()["y"])
spot = g.rgba([1.0, 1.0, 1.0], g.fill(g.circle(radius=0.2)))
g.output(g.layer(back["color"], spot))

Effects

Screen effects that return a number around 1: multiply your final color by them.

Vignette

vignette · Effects · g.vignette(...)

Darkens toward the corners: multiply a color by it.

Darkens toward the corners, drawing the eye to the center.

Input	Type	Default
uv	vec2	UV (context)
strength	float	0.8

Output	Type
value	float

Example

c = g.gradient(g.uv()["x"])
g.output(g.rgba(c["rgb"] * g.vignette(strength=0.9), 1.0))

Scanlines

scanlines · Effects · g.scanlines(...)

The horizontal lines of a CRT screen: multiply a color by it.

The horizontal lines of an old TV; speed makes them roll.

Input	Type	Default
px · pixel	vec2	Pixel (context)
spacing	float	3
strength	float	0.25
speed	float	0

Output	Type
value	float

Example

c = g.gradient(g.uv()["y"])
g.output(g.rgba(c["rgb"] * g.scanlines(spacing=3.0, strength=0.3), 1.0))

Film grain

grain · Effects · g.grain(...)

Random speckles that change every frame: multiply a color by it.

Random speckles that change every frame, like film.

Input	Type	Default
px · pixel	vec2	Pixel (context)
strength	float	0.12

Output	Type
value	float

Example

c = g.gradient(g.uv()["x"])
g.output(g.rgba(c["rgb"] * g.grain(strength=0.15), 1.0))

Texture

Images in a shader: add a texture variable (an image file) and read its colors.

Sample texture

sample_texture · Texture · g.sample_texture(...)

The color of a texture (an image variable) at uv.

Reads the color of an image at a UV. Add a texture variable whose value is an image path (relative to the .pzshad), wire it into texture, and warp the UV first for ripples or pixelation.

Input	Type	Default
texture	texture	—
uv	vec2	UV (context)

Output	Type
color	vec4
rgb	vec3
alpha	float

Example

photo = g.uniform("photo", "texture", "photo.png")
uv = g.pixelate(cells=[40.0, 30.0])
g.output(g.sample_texture(photo, uv["uv"]))

Always up to date

This page is generated from the node catalog of pyzed.shading, so the ports, types and defaults are always those of this version. Each example is compiled when the docs are built.

See also: Getting started · The Shader view · Recipes · Shader graphs in Python