Povray Backend

The povray backend generates high-quality, ray-traced snapshots of scenes by externally calling a povray binary. To use this backend, povray should be installed and accessible on your executable path.

class plato.draw.povray.Scene(primitives=[], features={}, size=(40, 30), translation=(0, 0, -50), rotation=(1, 0, 0, 0), zoom=1, pixel_scale=20, **kwargs)[source]

A container to hold and display collections of primitives.

Scene keeps track of global information about a set of things to be rendered and handles configuration of optional (possibly backend-specific) rendering parameters.

Global information managed by a Scene includes the size of the viewing window, translation and rotation applied to the scene as a whole, and a zoom level.

Primitives can be added to a scene through the primitives argument of the constructor or the add_primitive method. Primitives can be retrieved by iterating over the scene:

for prim in scene:
    # (do something with prim)

Primitives can also be accessed in the order they were added to the scene using list-like syntax:

first_three_prims = scene[:3]
last_prim = scene[-1]

Optional rendering arguments are enabled as features, which are name-value pairs identifying a feature by name and any configuration of the feature in the value.

This Scene supports the following features:

  • antialiasing: Enable antialiasing using the given value (default 0.3).
  • ambient_light: Enable trivial ambient lighting. The given value indicates the magnitude of the light (in [0, 1]).
  • directional_light: Add directional lights. The given value indicates the magnitude*direction normal vector.
  • multithreading: Enable multithreaded rendering. The given value indicates the number of threads to use.
render()[source]

Render all the shapes in this scene.

Returns:povray string representing the entire scene
save(filename)[source]

Save the scene, either as povray source or a rendered image.

Parameters:filename – target filename to save the result into. If filename ends in .pov, save the povray source, otherwise call povray to render the image
show()[source]

Render the scene to an image and display using ipython.

3D Graphics Primitives

class plato.draw.povray.Box(*args, **kwargs)[source]

A triclinic box frame.

This primitive draws a triclinic box centered at the origin. It is specified in terms of three lattice vector lengths Lx, Ly, Lz and tilt factors, defined using the hoomd-blue schema.

Rather than directly initializing via attributes, Box objects can also be automatically created from box-type objects using the from_box() method.

Examples:

Lx = Ly = Lz = 10
xy = xz = yz = 0
box_primitive = draw.Box(Lx=Lx, Ly=Ly, Lz=Lz, width=width, color=color)
box_tuple = (Lx, Ly, Lz, xy, xz, yz)
box_primitive = draw.Box.from_box(box_tuple)
This primitive has the following attributes:
  • start_points: Beginning coordinate for each line segment
  • end_points: Ending coordinate for each line segment
  • widths: Width of each line segment
  • colors: Color, RGBA, [0, 1] for each line segment
  • Lx: Length of first box vector
  • Ly: Length of second box vector
  • Lz: Length of third box vector
  • xy: Tilt factor between the first and second box vectors
  • xz: Tilt factor between the first and third box vectors
  • yz: Tilt factor between the second and third box vectors
  • width: Width of box line segments
  • color: Color, RGBA, [0, 1] for the box line segments
class plato.draw.povray.ConvexPolyhedra(**kwargs)[source]

A collection of identically-shaped convex polyhedra.

Each shape can have its own position, orientation, and color.

This primitive has the following attributes:
  • positions: Position of each particle
  • orientations: Orientation quaternion of each particle
  • colors: Color, RGBA, [0, 1] for each particle
  • vertices: Vertices in local coordinates for the shape, to be replicated for each particle
  • outline: Outline width for all shapes
  • outline: Outline width for all particles
colors

Color, RGBA, [0, 1] for each particle

orientations

Orientation quaternion of each particle

outline

Outline width for all particles

positions

Position of each particle

vertices

Vertices in local coordinates for the shape, to be replicated for each particle

class plato.draw.povray.ConvexSpheropolyhedra(**kwargs)[source]

A collection of identically-shaped convex spheropolyhedra.

Each shape can have its own position, orientation, and color. The rounding radius is shared over all shapes.

This primitive has the following attributes:
  • positions: Position of each particle
  • orientations: Orientation quaternion of each particle
  • colors: Color, RGBA, [0, 1] for each particle
  • vertices: Vertices in local coordinates for the interior (non-rounded) shape, to be replicated for each particle
  • radius: Rounding radius to be applied to all shapes
class plato.draw.povray.Ellipsoids(**kwargs)[source]

A collection of ellipsoids with identical dimensions.

Each ellipsoid can have its own position, orientation, and color. All shapes drawn by this primitive share common principal axis lengths.

This primitive has the following attributes:
  • positions: Position of each particle
  • orientations: Orientation quaternion of each particle
  • colors: Color, RGBA, [0, 1] for each particle
  • a: Radius in the x-direction
  • b: Radius in the y-direction
  • c: Radius in the z-direction
class plato.draw.povray.Lines(**kwargs)[source]

A collection of line segments.

Each segment can have a different color and width. Lines can be used in both 2D and 3D scenes, but they are currently not shaded and may look out of place in 3D.

This primitive has the following attributes:
  • start_points: Beginning coordinate for each line segment
  • end_points: Ending coordinate for each line segment
  • widths: Width of each line segment
  • colors: Color, RGBA, [0, 1] for each line segment
  • cap_mode: Cap mode for lines (0: default, 1: round)
cap_mode

Cap mode for lines (0: default, 1: round)

colors

Color, RGBA, [0, 1] for each line segment

end_points

Ending coordinate for each line segment

start_points

Beginning coordinate for each line segment

widths

Width of each line segment

class plato.draw.povray.Mesh(**kwargs)[source]

A 3D triangle mesh.

Meshes are specified by an array of vertices and indices identifying triangles within that vertex array. Colors are assigned per-vertex and interpolated between vertices.

Meshes with a common set of vertices and face indices can be replicated multiple times using a set of positions and orientations. In order to set the color of individual replicas of the Mesh object, use the shape_colors and shape_color_fraction attributes.

This primitive has the following attributes:
  • vertices: Vertex array specifying coordinates of the mesh nodes
  • indices: Indices of the vertex array specifying individual triangles (Nx3)
  • colors: Color, RGBA, [0, 1] for each vertex
  • positions: Central positions for each mesh to be replicated
  • orientations: Orientations for each mesh to be replicated
  • shape_colors: Color, RGBA, [0, 1] for each replica (shape) of the mesh
  • shape_color_fraction: Fraction of a vertex’s color that should be assigned based on shape_colors
class plato.draw.povray.Spheres(**kwargs)[source]

A collection of spheres in 3D.

Each sphere can have a different color and diameter.

This primitive has the following attributes:
  • positions: Position of each particle
  • colors: Color, RGBA, [0, 1] for each particle
  • radii: Radius of each particle
class plato.draw.povray.SphereUnions(**kwargs)[source]

A collection of identical sphere-union bodies in 3D.

A SphereUnions object is a union of spheres, each of which has its own color, radius, and local position. The SphereUnions object can be rigidly rotated and translated via its position and orientation attributes.

This primitive has the following attributes:
  • positions: Position of each particle
  • orientations: Orientation quaternion of each particle
  • colors: Color, RGBA, [0, 1] for each sphere in the union
  • points: Positions in local coordinates for the spheres in the union, to be replicated for each particle
  • radii: Radius of each sphere in the union