.. module:: freestyle.shaders
This module contains stroke shaders used for creation of stylized strokes. It is also intended to be a collection of examples for shader definition in Python.
User-defined stroke shaders inherit the :class:`freestyle.types.StrokeShader` class.
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`BackboneStretcherShader`
[Geometry shader]
.. method:: __init__(amount=2.0) Builds a BackboneStretcherShader object. :arg amount: The stretching amount value. :type amount: float
.. method:: shade(stroke) Stretches the stroke at its two extremities and following the respective directions: v(1)v(0) and v(n-1)v(n). :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`BezierCurveShader`
[Geometry shader]
.. method:: __init__(error=4.0)
Builds a BezierCurveShader object.
:arg error: The error we're allowing for the approximation. This
error is the max distance allowed between the new curve and the
original geometry.
:type error: float
.. method:: shade(stroke) Transforms the stroke backbone geometry so that it corresponds to a Bezier Curve approximation of the original backbone geometry. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`BlenderTextureShader`
[Texture shader]
.. method:: __init__(texture)
Builds a BlenderTextureShader object.
:arg texture: A line style texture slot or a shader node tree to define
a set of textures.
:type texture: :class:`bpy.types.LineStyleTextureSlot` or
:class:`bpy.types.ShaderNodeTree`
.. method:: shade(stroke) Assigns a blender texture slot to the stroke shading in order to simulate marks. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`CalligraphicShader`
[Thickness Shader]
.. method:: __init__(thickness_min, thickness_max, orientation, clamp)
Builds a CalligraphicShader object.
:arg thickness_min: The minimum thickness in the direction
perpendicular to the main direction.
:type thickness_min: float
:arg thickness_max: The maximum thickness in the main direction.
:type thickness_max: float
:arg orientation: The 2D vector giving the main direction.
:type orientation: :class:`mathutils.Vector`
:arg clamp: If true, the strokes are drawn in black when the stroke
direction is between -90 and 90 degrees with respect to the main
direction and drawn in white otherwise. If false, the strokes
are always drawn in black.
:type clamp: bool
.. method:: shade(stroke) Assigns thicknesses to the stroke vertices so that the stroke looks like made with a calligraphic tool, i.e. the stroke will be the thickest in a main direction, and the thinnest in the direction perpendicular to this one, and an interpolation in between. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`ColorNoiseShader`
[Color shader]
.. method:: __init__(amplitude, period) Builds a ColorNoiseShader object. :arg amplitude: The amplitude of the noise signal. :type amplitude: float :arg period: The period of the noise signal. :type period: float
.. method:: shade(stroke) Shader to add noise to the stroke colors. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`ConstantColorShader`
[Color shader]
.. method:: __init__(red, green, blue, alpha=1.0) Builds a ConstantColorShader object. :arg red: The red component. :type red: float :arg green: The green component. :type green: float :arg blue: The blue component. :type blue: float :arg alpha: The alpha value. :type alpha: float
.. method:: shade(stroke) Assigns a constant color to every vertex of the Stroke. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`ConstantThicknessShader`
[Thickness shader]
.. method:: __init__(thickness) Builds a ConstantThicknessShader object. :arg thickness: The thickness that must be assigned to the stroke. :type thickness: float
.. method:: shade(stroke) Assigns an absolute constant thickness to every vertex of the Stroke. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`ConstrainedIncreasingThicknessShader`
[Thickness shader]
.. method:: __init__(thickness_min, thickness_max, ratio) Builds a ConstrainedIncreasingThicknessShader object. :arg thickness_min: The minimum thickness. :type thickness_min: float :arg thickness_max: The maximum thickness. :type thickness_max: float :arg ratio: The thickness/length ratio that we don't want to exceed. :type ratio: float
.. method:: shade(stroke) Same as the :class:`IncreasingThicknessShader`, but here we allow the user to control the thickness/length ratio so that we don't get fat short lines. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`GuidingLinesShader`
[Geometry shader]
.. method:: __init__(offset)
Builds a GuidingLinesShader object.
:arg offset: The line that replaces the stroke is initially in the
middle of the initial stroke bounding box. offset is the value
of the displacement which is applied to this line along its
normal.
:type offset: float
.. method:: shade(stroke) Shader to modify the Stroke geometry so that it corresponds to its main direction line. This shader must be used together with the splitting operator using the curvature criterion. Indeed, the precision of the approximation will depend on the size of the stroke's pieces. The bigger the pieces are, the rougher the approximation is. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`IncreasingColorShader`
[Color shader]
.. method:: __init__(red_min, green_min, blue_min, alpha_min, red_max, green_max, blue_max, alpha_max) Builds an IncreasingColorShader object. :arg red_min: The first color red component. :type red_min: float :arg green_min: The first color green component. :type green_min: float :arg blue_min: The first color blue component. :type blue_min: float :arg alpha_min: The first color alpha value. :type alpha_min: float :arg red_max: The second color red component. :type red_max: float :arg green_max: The second color green component. :type green_max: float :arg blue_max: The second color blue component. :type blue_max: float :arg alpha_max: The second color alpha value. :type alpha_max: float
.. method:: shade(stroke) Assigns a varying color to the stroke. The user specifies two colors A and B. The stroke color will change linearly from A to B between the first and the last vertex. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`IncreasingThicknessShader`
[Thickness shader]
.. method:: __init__(thickness_A, thickness_B) Builds an IncreasingThicknessShader object. :arg thickness_A: The first thickness value. :type thickness_A: float :arg thickness_B: The second thickness value. :type thickness_B: float
.. method:: shade(stroke) Assigns thicknesses values such as the thickness increases from a thickness value A to a thickness value B between the first vertex to the midpoint vertex and then decreases from B to a A between this midpoint vertex and the last vertex. The thickness is linearly interpolated from A to B. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`PolygonalizationShader`
[Geometry shader]
.. method:: __init__(error)
Builds a PolygonalizationShader object.
:arg error: The error we want our polygonal approximation to have
with respect to the original geometry. The smaller, the closer
the new stroke is to the orinal one. This error corresponds to
the maximum distance between the new stroke and the old one.
:type error: float
.. method:: shade(stroke) Modifies the Stroke geometry so that it looks more "polygonal". The basic idea is to start from the minimal stroke approximation consisting in a line joining the first vertex to the last one and to subdivide using the original stroke vertices until a certain error is reached. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
.. method:: round_cap_thickness(x)
.. method:: shade(stroke)
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`SamplingShader`
[Geometry shader]
.. method:: __init__(sampling) Builds a SamplingShader object. :arg sampling: The sampling to use for the stroke resampling. :type sampling: float
.. method:: shade(stroke) Resamples the stroke. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`SmoothingShader`
[Geometry shader]
.. method:: __init__(num_iterations=100, factor_point=0.1, \
factor_curvature=0.0, factor_curvature_difference=0.2, \
aniso_point=0.0, aniso_normal=0.0, aniso_curvature=0.0, \
carricature_factor=1.0)
Builds a SmoothingShader object.
:arg num_iterations: The number of iterations.
:type num_iterations: int
:arg factor_point: 0.1
:type factor_point: float
:arg factor_curvature: 0.0
:type factor_curvature: float
:arg factor_curvature_difference: 0.2
:type factor_curvature_difference: float
:arg aniso_point: 0.0
:type aniso_point: float
:arg aniso_normal: 0.0
:type aniso_normal: float
:arg aniso_curvature: 0.0
:type aniso_curvature: float
:arg carricature_factor: 1.0
:type carricature_factor: float
.. method:: shade(stroke) Smoothes the stroke by moving the vertices to make the stroke smoother. Uses curvature flow to converge towards a curve of constant curvature. The diffusion method we use is anisotropic to prevent the diffusion across corners. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`SpatialNoiseShader`
[Geometry shader]
.. method:: __init__(amount, scale, num_octaves, smooth, pure_random) Builds a SpatialNoiseShader object. :arg amount: The amplitude of the noise. :type amount: float :arg scale: The noise frequency. :type scale: float :arg num_octaves: The number of octaves :type num_octaves: int :arg smooth: True if you want the noise to be smooth. :type smooth: bool :arg pure_random: True if you don't want any coherence. :type pure_random: bool
.. method:: shade(stroke) Spatial Noise stroke shader. Moves the vertices to make the stroke more noisy. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
.. method:: shade(stroke)
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`StrokeTextureStepShader`
[Texture shader]
.. method:: __init__(step) Builds a StrokeTextureStepShader object. :arg step: The spacing along the stroke. :type step: float
.. method:: shade(stroke) Assigns a spacing factor to the texture coordinates of the Stroke. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`ThicknessNoiseShader`
[Thickness shader]
.. method:: __init__(amplitude, period) Builds a ThicknessNoiseShader object. :arg amplitude: The amplitude of the noise signal. :type amplitude: float :arg period: The period of the noise signal. :type period: float
.. method:: shade(stroke) Adds some noise to the stroke thickness. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Class hierarchy: :class:`freestyle.types.StrokeShader` > :class:`TipRemoverShader`
[Geometry shader]
.. method:: __init__(tip_length)
Builds a TipRemoverShader object.
:arg tip_length: The length of the piece of stroke we want to remove
at each extremity.
:type tip_length: float
.. method:: shade(stroke) Removes the stroke's extremities. :arg stroke: A Stroke object. :type stroke: :class:`freestyle.types.Stroke`
Assigns a color (grayscale) to the stroke based on the curvature. A higher curvature will yield a brighter color.
.. method:: shade(stroke)
Stretches the stroke's backbone, excluding cusp vertices (end junctions).
.. method:: shade(stroke)
Stretches the stroke's backbone by a given length (in pixels).
.. method:: shade(stroke)
Draws the silhouette of the object as a circle.
.. method:: shade(stroke)
Replaces the stroke with a directed square.
.. method:: shade(stroke)
.. method:: shade(stroke)
.. method:: shade(stroke)
Assigns a constant color to the stroke.
.. method:: shade(stroke)
Assigns a constant thickness along the stroke.
.. method:: shade(stroke)
Increasingly thickens the stroke, constrained by a ratio of the stroke's length.
.. method:: shade(stroke)
Inverse of pyIncreasingThicknessShader, decreasingly thickens the stroke.
.. method:: shade(stroke)
Assigns a thickness to the stroke based on the stroke's distance to the camera (Z-value).
.. method:: shade(stroke)
Iteratively adds an offset to the position of each stroke vertex in the direction perpendicular to the stroke direction at the point. The offset is scaled by the 2D curvature (i.e. how quickly the stroke curve is) at the point.
.. method:: shade(stroke)
Assigns thickness to a stroke based on the density of the diffuse map.
.. method:: shade(stroke)
.. method:: shade(stroke)
Controls visibility based upon the quantitative invisibility (QI) based on hidden line removal (HLR).
.. method:: shade(stroke)
Assigns thickness based on distance to a given point in 2D space. the thickness is inverted, so the vertices closest to the specified point have the lowest thickness.
.. method:: shade(stroke)
Assigns thickness based on distance to a given point in 3D space.
.. method:: shade(stroke)
Fades from one color to another along the stroke.
.. method:: shade(stroke)
Increasingly thickens the stroke.
.. method:: shade(stroke)
Fades from one color to another and back.
.. method:: shade(stroke)
Stretches the stroke's backbone proportional to the stroke's length NOTE: you'll probably want an l somewhere between (0.5 - 0). A value that is too high may yield unexpected results.
.. method:: shade(stroke)
Assigns the color of the underlying material to the stroke.
.. method:: shade(stroke)
Limits the stroke's alpha between a min and max value.
.. method:: shade(stroke)
Assigns thickness to a stroke based on an exponential function.
.. method:: shade(stroke)
Displaces the stroke using the curvilinear abscissa. This means that lines with the same length and sampling interval will be identically distorded.
.. method:: shade(stroke)
Displaces the stroke using the strokes coordinates. This means that in a scene no strokes will be distorded identically.
More information on the noise shaders can be found at: freestyleintegration.wordpress.com/2011/09/25/development-updates-on-september-25/
.. method:: shade(stroke)
Assigns a color to the stroke based on given seed.
.. method:: shade(stroke)
Assigns thickness to a stroke based on spherical linear interpolation.
.. method:: shade(stroke)
Resamples the stroke, which gives the stroke the amount of vertices specified.
.. method:: shade(stroke)
Displaces the stroke in the shape of a sine wave.
.. method:: shade(stroke)
Removes t-vertices from the stroke.
.. method:: shade(stroke)
Thickens TVertices (visual intersections between two edges).
.. method:: shade(stroke)
Assigns a grayscale value that increases for every vertex. The brightness will increase along the stroke.
.. method:: shade(stroke)
Removes the tips of the stroke.
.. method:: shade(stroke)
Undocumented
Assigns thickness based on an object's local Z depth (point closest to camera is 1, point furthest from camera is zero).
.. method:: shade(stroke)