python-scientific 2.8-4 / usr / share / pyshared / Scientific / Visualization / VRML2.py

# This module provides classes that represent VRML objects for use
# in data visualization applications.
#
# Written by: Konrad Hinsen <hinsen@cnrs-orleans.fr>
# With contributions from Frank Horowitz
#                     and Matteo Bertini
# Last revision: 2006-9-12
#

"""
Definitions of simple 3D graphics objects and VRML scenes containing them

The objects are appropriate for data visualization, not for virtual
reality modelling. Scenes can be written to VRML files or visualized
immediately using a VRML browser, whose name is taken from the
environment variable VRML2VIEWER (under Unix).

This module uses the VRML 2.0 definition, also known as VRML97. For
the original VRML 1, use the module VRML, which uses exactly the same
interface.

Example::

  >>> from Scientific.Visualization.VRML import *    
  >>> scene = Scene([])
  >>> scale = ColorScale(10.)
  >>> for x in range(11):
  >>>     color = scale(x)
  >>>     scene.addObject(Cube(Vector(x, 0., 0.), 0.2,
  >>>                          material=Material(diffuse_color = color)))
  >>> scene.view()
"""

from Scientific.IO.TextFile import TextFile
from Scientific.Geometry import Transformation, Vector, ex, ey, ez
from Scientific import N
import os, string, tempfile

from Color import *

#
# VRML file
#
class SceneFile:

    def __init__(self, filename, mode = 'r'):
        if mode == 'r':
            raise TypeError, 'Not implemented.'
        self.file = TextFile(filename, 'w')
        self.file.write('#VRML V2.0 utf8\n')
        self.file.write('Transform { children [\n')
        self.memo = {}
        self.name_counter = 0

    def __del__(self):
        self.close()

    def writeString(self, data):
        self.file.write(data)

    def close(self):
        if self.file is not None:
            self.file.write(']}\n')
            self.file.close()
            self.file = None

    def write(self, object):
        object.writeToFile(self)

    def uniqueName(self):
        self.name_counter = self.name_counter + 1
        return 'i' + `self.name_counter`

VRMLFile = SceneFile

#
# Scene
#
class Scene:

    """
    VRML scene

    A VRML scene is a collection of graphics objects that can be
    written to a VRML file or fed directly to a VRML browser.
    """

    def __init__(self, objects = None, cameras = None, **options):
        """
        @param objects: a list of graphics objects, or C{None} for
                        an empty scene
        @type objects: C{list} or C{NoneType}
        @param cameras: a list of cameras, or C{None} for no cameras
        @param options: options as keyword arguments (none defined)
        """
        if objects is None:
            self.objects = []
        elif type(objects) == type([]):
            self.objects = objects
        else:
            self.objects = [objects]
        if cameras is None:
            self.cameras = []
        else:
            self.cameras = cameras

    def __len__(self):
        """
        @returns: the number of graphics objects in the scene
        @rtype: C{int}
        """
        return len(self.objects)

    def __getitem__(self, item):
        """
        @param item: an index
        @type item: C{int}
        @returns: the graphics object at the index position
        @rtype: L{VRMLObject}
        """
        return self.object[item]

    def addObject(self, object):
        """
        @param object: a graphics object to be added to the scene
        @type object: L{VRMLObject}
        """
        self.objects.append(object)

    def addCamera(self, camera):
        """
        Add a camera to the list of cameras
        @param camera: the camera to be adde
        """
        self.cameras.append(camera)

    def writeToFile(self, filename):
        """
        Write the scene to a VRML file

        @param filename: the name of the script
        @type filename: C{str}
        """
        file = VRMLFile(filename, 'w')
        if self.cameras:
            for camera in self.cameras:
                camera.writeToFile(file)
        for o in self.objects:
            o.writeToFile(file)
        file.close()

    def view(self, *args):
        """
        Start a VRML browser and load the scene

        @param args: not used, for compatibility only
        """
        import sys
        filename = tempfile.mktemp()+'.wrl'
        if sys.platform == 'win32':
            import win32api
            self.writeToFile(filename)
            win32api.ShellExecute(0, "open", filename, None, "", 1)
        elif os.environ.has_key('VRML2VIEWER'):
            self.writeToFile(filename)
            if os.fork() == 0:
                os.system(os.environ['VRML2VIEWER'] + ' ' + filename +
                          ' 1> /dev/null 2>&1')
                os.unlink(filename)
                os._exit(0)
        else:
            print 'No VRML2 viewer defined'

#
# Camera class
#
class Camera:

    """
    Camera/viewpoint for a scene
    """

    def __init__(self, position=None, orientation=None,
                 description=None, field_of_view=None):
        """
        @param position: the location of the camera
        @type position: L{Scientific.Geometry.Vector}
        @param orientation: an (axis, angle) tuple in which the axis is
                            a vector and the angle a number in radians;
                            axis and angle specify a rotation with respect
                            to the standard orientation along the negative
                            z axis
        @param description: a label for the viewpoint
        @type description: C{str}
        @param field_of_view: the field of view
        @type field_of_view: positive number
        """
        self.field_of_view = field_of_view
        self.orientation = orientation
        self.position = position
        self.description = description

    def writeToFile(self, file):
        file.writeString('Viewpoint {\n')
        if self.field_of_view != None:
            file.writeString('fieldOfView %f\n' % self.field_of_view)
        if self.orientation != None:
            axis, angle = self.orientation
            axis = axis.normal()
            file.writeString('orientation %f %f %f %f\n' % \
                             (axis[0], axis[1], axis[2], angle))
        if self.position != None:
            file.writeString('position %f %f %f\n' % \
                             (self.position[0], \
                              self.position[1], \
                              self.position[2]))
        if self.description != None:
            file.writeString('description "%s"' % \
                             self.description)
        file.writeString('}\n')

#
# Navigation Info
#
class NavigationInfo:

    """
    Navigation information
    """

    def __init__(self, speed=100.0, type="EXAMINE"):
        """
        @param speed: walking speed in length units per second
        @type speed: number
        @param type: one of 'WALK', 'EXAMINE', 'FLY', 'NONE', 'ANY'
        """
        self.speed = speed
        self.type = type

    def writeToFile(self, file):
        file.writeString('NavigationInfo {\n')
        file.writeString('speed %f\n' % self.speed )
        file.writeString('type [ ')
        if self.type != "ANY":
            file.writeString('"%s", ' % self.type)
        file.writeString('"ANY" ]\n')
        file.writeString('}\n')

#
# Base class for everything that produces nodes
#
class VRMLObject:

    """
    Graphics object for VRML

    This is an abstract base class. Use one of the subclasses to generate
    graphics.
    """

    def __init__(self, attr):
        """
        @param attr: graphics attributes specified by keywords
        @keyword material: color and surface properties
        @type material: L{Material}
        @keyword comment: a comment that is written to the script file
        @type comment: C{str}
        @keyword reuse: a flag defaulting to C{False}. If set to C{True},
                        the object may share its VRML definition with other
                        objects. This reduces the size of the VRML file, but
                        can yield surprising side effects in some cases.
        @type reuse: C{bool}
        """
        self.attr = {}
        for key, value in attr.items():
            if key in self.attribute_names:
                self.attr[key] = value
            else:
                raise AttributeError, 'illegal attribute: ' + str(key)

    attribute_names = ['comment']

    def __getitem__(self, attr):
        """
        @param attr: the name of a graphics attribute
        @type attr: C{str}
        @returns: the value of the attribute, or C{None} if the attribute
                  is undefined
        """
        try:
            return self.attr[attr]
        except KeyError:
            return None

    def __setitem__(self, attr, value):
        """
        @param attr: the name of a graphics attribute
        @type attr: C{str}
        @param value: a new value for the attribute
        """
        self.attr[attr] = value

    def __copy__(self):
        return copy.deepcopy(self)

    def writeToFile(self, file):
        raise AttributeError, 'Class ' + self.__class__.__name__ + \
              ' does not implement file output.'

#
# Shapes
#
class ShapeObject(VRMLObject):

    """
    Graphics objects representing geometrical shapes

    This is an abstract base class. Use one of the subclasses to generate
    graphics.
    """

    def __init__(self, attr, rotation, translation, reference_point):
        VRMLObject.__init__(self, attr)
        if rotation is None:
            rotation = Transformation.Rotation(ez, 0.)
        else:
            rotation = apply(Transformation.Rotation, rotation)
        if translation is None:
            translation = Transformation.Translation(Vector(0.,0.,0.))
        else:
            translation = Transformation.Translation(translation)
        self.transformation = translation*rotation
        self.reference_point = reference_point

    attribute_names = VRMLObject.attribute_names + ['material', 'reuse']

    def __add__(self, other):
        return Group([self]) + Group([other])

    def writeToFile(self, file):
        comment = self['comment']
        if comment is not None:
            file.writeString('# ' + comment + '\n')
        file.writeString('Transform{\n')
        vector = self.transformation.translation().displacement()
        axis, angle = self.transformation.rotation().axisAndAngle()
        trans_flag = vector.length() > 1.e-4
        rot_flag = abs(angle) > 1.e-4
        if trans_flag:
            file.writeString('translation %f %f %f\n' %
                                (vector[0], vector[1], vector[2]))
        if rot_flag:
            file.writeString('rotation %f %f %f %f\n' %
                                (axis[0], axis[1], axis[2], angle))
        material = self['material']
        reuse = self['reuse']
        file.writeString('children [\n')
        if reuse:
            key = self.memoKey() + (material, self.__class__)
            if file.memo.has_key(key):
                file.writeString('USE ' + file.memo[key] + '\n')
                self.use(file)
                if material is not None:
                    material.use(file)
            else:
                name = file.uniqueName()
                file.memo[key] = name
                file.writeString('DEF ' + name + ' Shape{\n')
                if material is not None:
                    file.writeString('appearance ')
                    material.writeToFile(file)
                file.writeString('geometry ')
                self.writeSpecification(file)
                file.writeString('}\n')
        else:
            file.writeString('Shape{')
            if material is not None:
                file.writeString('appearance ')
                material.writeToFile(file)
            file.writeString('geometry ')
            self.writeSpecification(file)
            file.writeString('}\n')
        file.writeString(']}\n')

    def use(self, file):
        pass

class Sphere(ShapeObject):

    """
    Sphere
    """
    
    def __init__(self, center, radius, **attr):
        """
        @param center: the center of the sphere
        @type center: L{Scientific.Geometry.Vector}
        @param radius: the sphere radius
        @type radius: positive number
        @param attr: graphics attributes as keyword parameters
        """
        self.radius = radius
        ShapeObject.__init__(self, attr, None, center, center)

    def writeSpecification(self, file):
        file.writeString('Sphere{radius ' + `self.radius` + '}\n')

    def memoKey(self):
        return (self.radius, )

class Cube(ShapeObject):

    """
    Cube

    The edges of a cube are always parallel to the coordinate axes.
    """
    
    def __init__(self, center, edge, **attr):
        """
        @param center: the center of the sphere
        @type center: L{Scientific.Geometry.Vector}
        @param edge: the length of an edge
        @type edge: positive number
        @param attr: graphics attributes as keyword parameters
        """
        self.edge = edge
        ShapeObject.__init__(self, attr, None, center, center)

    def writeSpecification(self, file):
        file.writeString('Box{size' + 3*(' ' + `self.edge`) + '}\n')

    def memoKey(self):
        return (self.edge, )

class LinearOrientedObject(ShapeObject):

    def __init__(self, attr, point1, point2):
        center = 0.5*(point1+point2)
        axis = point2-point1
        self.height = axis.length()
        if self.height > 0:
            axis = axis/self.height
            rot_axis = ey.cross(axis)
            sine = rot_axis.length()
            cosine = ey*axis
            angle = Transformation.angleFromSineAndCosine(sine, cosine)
            if abs(angle) < 1.e-4 or abs(angle-2.*N.pi) < 1.e-4:
                rotation = None
            else:
                if abs(sine) < 1.e-4:
                    rot_axis = ex
                rotation = (rot_axis, angle)
        else:
            rotation = None
        ShapeObject.__init__(self, attr, rotation, center, center)

class Cylinder(LinearOrientedObject):

    """
    Cylinder
    """

    def __init__(self, point1, point2, radius, faces = (True, True, True),
                 **attr):
        """
        @param point1: first end point of the cylinder axis
        @type point1: L{Scientific.Geometry.Vector}
        @param point2: second end point of the cylinder axis
        @type point2: L{Scientific.Geometry.Vector}
        @param radius: the cylinder radius
        @type radius: positive number
        @param faces: a sequence of three boolean flags, corresponding to
                      the cylinder hull and the two circular end pieces,
                      specifying for each of these parts whether it is visible
                      or not
        @param attr: graphics attributes as keyword parameters
        """
        self.faces = faces
        self.radius = radius
        LinearOrientedObject.__init__(self, attr, point1, point2)

    def writeSpecification(self, file):
        file.writeString('Cylinder{')
        if not self.faces[0]:
            file.writeString('side FALSE ')
        if not self.faces[1]:
            file.writeString('bottom FALSE ')
        if not self.faces[2]:
            file.writeString('top FALSE ')
        file.writeString('radius ' + `self.radius` + \
                         ' height ' + `self.height` + '}\n')

    def memoKey(self):
        return (self.radius, self.height, self.faces)


class Cone(LinearOrientedObject):

    """
    Cone
    """

    def __init__(self, point1, point2, radius, face = True, **attr):
        """
        @param point1: the tip of the cone
        @type point1: L{Scientific.Geometry.Vector}
        @param point2: end point of the cone axis
        @type point2: L{Scientific.Geometry.Vector}
        @param radius: the radius at the base
        @type radius: positive number
        @param face: a boolean flag, specifying if the circular
                      bottom is visible
        @type face: C{bool}
        @param attr: graphics attributes as keyword parameters
        """
        self.face = face
        self.radius = radius
        LinearOrientedObject.__init__(self, attr, point2, point1)

    def writeSpecification(self, file):
        file.writeString('Cone{')
        if not self.face:
            file.writeString('bottom FALSE ')
        file.writeString('bottomRadius ' + `self.radius` + \
                         ' height ' + `self.height` + '}\n')

    def memoKey(self):
        return (self.radius, self.height, self.face)

class Line(ShapeObject):

    """
    Line
    """
    
    def __init__(self, point1, point2, **attr):
        """
        @param point1: first end point
        @type point1: L{Scientific.Geometry.Vector}
        @param point2: second end point
        @type point2: L{Scientific.Geometry.Vector}
        @param attr: graphics attributes as keyword parameters
        """
        self.points = (point1, point2)
        center = 0.5*(point1+point2)
        ShapeObject.__init__(self, attr, None, None, center)

    def writeSpecification(self, file):
        p0 = "%f %f %f" % tuple(self.points[0])
        p1 = "%f %f %f" % tuple(self.points[1])
        file.writeString('IndexedLineSet{coord Coordinate{point ')
        file.writeString('[%s,\n%s]} coordIndex[0,1,-1]}\n' % (p0, p1))

    def memoKey(self):
        return tuple(self.points[0]) + tuple(self.points[1])

class PolyLines(ShapeObject):

    """
    Multiple connected lines
    """
    
    def __init__(self, points, **attr):
        """
        @param points: a sequence of points to be connected by lines
        @type points: sequence of L{Scientific.Geometry.Vector}
        @param attr: graphics attributes as keyword parameters
        """
        self.points = points
        ShapeObject.__init__(self, attr, None, None, Vector(0., 0., 0.))

    def writeSpecification(self, file):
        s = ['IndexedLineSet{coord Coordinate{point [',]
        for p in self.points:
            s.append('%f %f %f,' % (p[0], p[1], p[2]))
        s[-1] = s[-1][:-1] + ']} coordIndex'
        file.writeString("\n".join(s))
        file.writeString(`range(len(self.points))+[-1]` + '}\n')

    def memoKey(self):
        return tuple(map(tuple, self.points))


class Polygons(ShapeObject):

    """
    Polygons
    """
    
    def __init__(self, points, index_lists, **attr):
        """
        @param points: a sequence of points
        @type points: sequence of L{Scientific.Geometry.Vector}
        @param index_lists: a sequence of index lists, one for each polygon.
                            The index list for a polygon defines which points
                            are vertices of the polygon.
        @type index_lists: sequence of C{list}
        @param attr: graphics attributes as keyword parameters
        """
        self.points = points
        self.index_lists = index_lists
        ShapeObject.__init__(self, attr, None, None, Vector(0.,0.,0.))

    def writeSpecification(self, file):
        s = ['IndexedFaceSet{coord Coordinate{point [',]
        for v in self.points[:-1]:
            s.append('%f %f %f,' % (v[0], v[1], v[2]))
        v = self.points[-1]
        s.append('%f %f %f\n]} coordIndex[' % (v[0], v[1], v[2]))
        for polygon in self.index_lists:
            s.append(",".join(map(str, polygon) + ["-1,"]))
        s.append(']}\n')
        file.writeString("\n".join(s))

    def memoKey(self):
        return (tuple(map(tuple, self.points)),
                tuple(map(tuple, self.index_lists)))

#
# Groups
#
class Group:

    """
    Base class for composite objects
    """

    def __init__(self, objects, **attr):
        self.objects = []
        for o in objects:
            if isGroup(o):
                self.objects = self.objects + o.objects
            else:
                self.objects.append(o)
        for key, value in attr.items():
            for o in self.objects:
                o[key] = value

    is_group = 1

    def __len__(self):
        return len(self.objects)

    def __getitem__(self, item):
        return self.object[item]

    def __coerce__(self, other):
        if not isGroup(other):
            other = Group([other])
        return (self, other)

    def __add__(self, other):
        return Group(self.objects + other.objects)

    def writeToFile(self, file):
        for o in self.objects:
            o.writeToFile(file)

def isGroup(x):
    return hasattr(x, 'is_group')

#
# Composite Objects
#
class Arrow(Group):

    """
    Arrow

    An arrow consists of a cylinder and a cone.
    """

    def __init__(self, point1, point2, radius, **attr):
        """
        @param point1: starting point of the arrow
        @type point1: L{Scientific.Geometry.Vector}
        @param point2: the tip of the arrow
        @type point2: L{Scientific.Geometry.Vector}
        @param radius: the radius of the shaft
        @type radius: positive number
        @param attr: graphics attributes as keyword parameters
        """
        axis = point2-point1
        height = axis.length()
        axis = axis/height
        cone_height = min(height, 4.*radius)
        cylinder_height = height - cone_height
        junction = point2-axis*cone_height
        cone = apply(Cone, (point2, junction, 0.75*cone_height), attr)
        objects = [cone]
        if cylinder_height > 0.005*radius:
            cylinder = apply(Cylinder, (point1, junction, radius), attr)
            objects.append(cylinder)
        Group.__init__(self, objects)

#
# Materials
#
class Material(VRMLObject):

    """
    Material specification for graphics objects

    A material defines the color and surface properties of an object.
    """

    def __init__(self, **attr):
        """
        @param attr: material attributes as keyword arguments
        @keyword diffuse_color: the color of a diffusely reflecting surface
        @type diffuse_color: L{Color}
        @keyword emissive_color: the color of emitted light
        @type emissive_color: L{Color}
        @keyword ambient_color: 
        @type ambient_color: L{Color}
        @keyword specular_color: 
        @type specular_color: L{Color}
        @keyword shininess:
        @type shininess: C{float}
        @keyword transparency: 
        @type transparency: C{float}
        """
        VRMLObject.__init__(self, attr)

    attribute_names = VRMLObject.attribute_names + \
                      ['ambient_color', 'diffuse_color', 'specular_color',
                       'emissive_color', 'shininess', 'transparency']

    attribute_conversion = {'ambient_color': 'ambientColor',
                            'diffuse_color': 'diffuseColor',
                            'specular_color': 'specularColor',
                            'emissive_color': 'emissiveColor',
                            'shininess': 'shininess',
                            'transparency': 'transparency'}

    def writeToFile(self, file):
        if file.memo.has_key(self):
            file.writeString('USE ' + file.memo[self] + '\n')
        else:
            name = file.uniqueName()
            file.memo[self] = name
            file.writeString('DEF '+name+' Appearance{material Material{\n')
            for key, value in self.attr.items():
                file.writeString(self.attribute_conversion[key] + ' ' + \
                                 str(value) + '\n')
            file.writeString('}}\n')

    def use(self, file):
        pass

#
# Predefined materials
#
def DiffuseMaterial(color):
    """
    @param color: a color object or a predefined color name
    @type color: L{Color} or C{str}
    @returns: a material with the 'diffuse color' attribute set to color
    @rtype: L{Material}
    """
    if type(color) is type(''):
        color = ColorByName(color)
    try:
        return _diffuse_material_dict[color]
    except KeyError:
        m = Material(diffuse_color = color)
        _diffuse_material_dict[color] = m
        return m

_diffuse_material_dict = {}

def EmissiveMaterial(color):
    """
    @param color: a color object or a predefined color name
    @type color: L{Color} or C{str}
    @returns: a material with the 'emissive color' attribute set to color
    @rtype: L{Material}
    """
    if type(color) is type(''):
        color = ColorByName(color)
    try:
        return _emissive_material_dict[color]
    except KeyError:
        m = Material(emissive_color = color)
        _emissive_material_dict[color] = m
        return m

_emissive_material_dict = {}


#
# Test code
#
if __name__ == '__main__':

    if 1:
        from Scientific.Geometry import null, ex, ey, ez
        spheres = DiffuseMaterial('green')
        links = DiffuseMaterial('red')
        s1 = Sphere(null, 0.05, material = spheres, reuse = 1)
        s2 = Sphere(ex, 0.05, material = spheres, reuse = 1)
        s3 = Sphere(ey, 0.05, material = spheres, reuse = 1)
        s4 = Sphere(ez, 0.05, material = spheres, reuse = 1)
        a1 = Arrow(null, ex, 0.01, material = links)
        a2 = Arrow(null, ey, 0.01, material = links)
        a3 = Arrow(null, ez, 0.01, material = links)
        scene = Scene([a1, a2, a3, s1, s2, s3, s4])
        scene.view()

    if 0:
        scene = Scene([])
        scale = ColorScale(10.)
        for x in range(11):
            color = scale(x)
            m = Material(diffuse_color = color)
            scene.addObject(Cube(Vector(x,0.,0.), 0.2, material=m))
        scene.view()

    if 0:
        points = [Vector(0., 0., 0.),
                  Vector(0., 1., 0.),
                  Vector(1., 1., 0.),
                  Vector(1., 0., 0.),
                  Vector(1., 0., 1.),
                  Vector(1., 1., 1.)]
        indices = [[0, 1, 2, 3, 0], [3, 4, 5, 2, 3]]
        scene = Scene(Polygons(points, indices,
                               material=DiffuseMaterial('yellow')))
        scene.view()

    if 0:
        points = [Vector(0., 0., 0.),
                  Vector(0., 1., 0.),
                  Vector(1., 1., 0.),
                  Vector(1., 0., 0.),
                  Vector(1., 0., 1.),
                  Vector(1., 1., 1.)]
        scene = Scene(PolyLines(points, material = EmissiveMaterial('yellow')))
        scene.view()