def scalar_bar(lookup_table=None, title=" "): """ Default scalar bar actor for a given colormap (colorbar) Parameters ---------- lookup_table : vtkLookupTable or None If None then ``colormap_lookup_table`` is called with default options. title : str Returns ------- scalar_bar : vtkScalarBarActor See Also -------- :func:`dipy.viz.actor.colormap_lookup_table` """ lookup_table_copy = vtk.vtkLookupTable() if lookup_table is None: lookup_table = colormap_lookup_table() # Deepcopy the lookup_table because sometimes vtkPolyDataMapper deletes it lookup_table_copy.DeepCopy(lookup_table) scalar_bar = vtk.vtkScalarBarActor() scalar_bar.SetTitle(title) scalar_bar.SetLookupTable(lookup_table_copy) scalar_bar.SetNumberOfLabels(6) return scalar_bar
def line(lines, colors=None, opacity=1, linewidth=1, spline_subdiv=None, lod=True, lod_points=10 ** 4, lod_points_size=3, lookup_colormap=None): """ Create an actor for one or more lines. Parameters ------------ lines : list of arrays colors : array (N, 3), list of arrays, tuple (3,), array (K,), None If None then a standard orientation colormap is used for every line. If one tuple of color is used. Then all streamlines will have the same colour. If an array (N, 3) is given, where N is equal to the number of lines. Then every line is coloured with a different RGB color. If a list of RGB arrays is given then every point of every line takes a different color. If an array (K, ) is given, where K is the number of points of all lines then these are considered as the values to be used by the colormap. If an array (L, ) is given, where L is the number of streamlines then these are considered as the values to be used by the colormap per streamline. If an array (X, Y, Z) or (X, Y, Z, 3) is given then the values for the colormap are interpolated automatically using trilinear interpolation. opacity : float, optional Default is 1. linewidth : float, optional Line thickness. Default is 1. spline_subdiv : int, optional Number of splines subdivision to smooth streamtubes. Default is None which means no subdivision. lod : bool Use vtkLODActor(level of detail) rather than vtkActor. Default is True. Level of detail actors do not render the full geometry when the frame rate is low. lod_points : int Number of points to be used when LOD is in effect. Default is 10000. lod_points_size : int Size of points when lod is in effect. Default is 3. lookup_colormap : bool, optional Add a default lookup table to the colormap. Default is None which calls :func:`dipy.viz.actor.colormap_lookup_table`. Returns ---------- v : vtkActor or vtkLODActor object Line. Examples ---------- >>> from dipy.viz import actor, window >>> ren = window.Renderer() >>> lines = [np.random.rand(10, 3), np.random.rand(20, 3)] >>> colors = np.random.rand(2, 3) >>> c = actor.line(lines, colors) >>> ren.add(c) >>> #window.show(ren) """ # Poly data with lines and colors poly_data, is_colormap = lines_to_vtk_polydata(lines, colors) next_input = poly_data # use spline interpolation if (spline_subdiv is not None) and (spline_subdiv > 0): spline_filter = set_input(vtk.vtkSplineFilter(), next_input) spline_filter.SetSubdivideToSpecified() spline_filter.SetNumberOfSubdivisions(spline_subdiv) spline_filter.Update() next_input = spline_filter.GetOutputPort() poly_mapper = set_input(vtk.vtkPolyDataMapper(), next_input) poly_mapper.ScalarVisibilityOn() poly_mapper.SetScalarModeToUsePointFieldData() poly_mapper.SelectColorArray("Colors") poly_mapper.Update() # Color Scale with a lookup table if is_colormap: if lookup_colormap is None: lookup_colormap = colormap_lookup_table() poly_mapper.SetLookupTable(lookup_colormap) poly_mapper.UseLookupTableScalarRangeOn() poly_mapper.Update() # Set Actor if lod: actor = vtk.vtkLODActor() actor.SetNumberOfCloudPoints(lod_points) actor.GetProperty().SetPointSize(lod_points_size) else: actor = vtk.vtkActor() # actor = vtk.vtkActor() actor.SetMapper(poly_mapper) actor.GetProperty().SetLineWidth(linewidth) actor.GetProperty().SetOpacity(opacity) return actor
def slicer(data, affine=None, value_range=None, opacity=1., lookup_colormap=None, interpolation='linear'): """ Cuts 3D scalar or rgb volumes into 2D images Parameters ---------- data : array, shape (X, Y, Z) or (X, Y, Z, 3) A grayscale or rgb 4D volume as a numpy array. affine : array, shape (4, 4) Grid to space (usually RAS 1mm) transformation matrix. Default is None. If None then the identity matrix is used. value_range : None or tuple (2,) If None then the values will be interpolated from (data.min(), data.max()) to (0, 255). Otherwise from (value_range[0], value_range[1]) to (0, 255). opacity : float Opacity of 0 means completely transparent and 1 completely visible. lookup_colormap : vtkLookupTable If None (default) then a grayscale map is created. interpolation : string If 'linear' (default) then linear interpolation is used on the final texture mapping. If 'nearest' then nearest neighbor interpolation is used on the final texture mapping. Returns ------- image_actor : ImageActor An object that is capable of displaying different parts of the volume as slices. The key method of this object is ``display_extent`` where one can input grid coordinates and display the slice in space (or grid) coordinates as calculated by the affine parameter. """ if data.ndim != 3: if data.ndim == 4: if data.shape[3] != 3: raise ValueError('Only RGB 3D arrays are currently supported.') else: nb_components = 3 else: raise ValueError('Only 3D arrays are currently supported.') else: nb_components = 1 if value_range is None: vol = np.interp(data, xp=[data.min(), data.max()], fp=[0, 255]) else: vol = np.interp(data, xp=[value_range[0], value_range[1]], fp=[0, 255]) vol = vol.astype('uint8') im = vtk.vtkImageData() if major_version <= 5: im.SetScalarTypeToUnsignedChar() I, J, K = vol.shape[:3] im.SetDimensions(I, J, K) voxsz = (1., 1., 1.) # im.SetOrigin(0,0,0) im.SetSpacing(voxsz[2], voxsz[0], voxsz[1]) if major_version <= 5: im.AllocateScalars() im.SetNumberOfScalarComponents(nb_components) else: im.AllocateScalars(vtk.VTK_UNSIGNED_CHAR, nb_components) # copy data # what I do below is the same as what is commented here but much faster # for index in ndindex(vol.shape): # i, j, k = index # im.SetScalarComponentFromFloat(i, j, k, 0, vol[i, j, k]) vol = np.swapaxes(vol, 0, 2) vol = np.ascontiguousarray(vol) if nb_components == 1: vol = vol.ravel() else: vol = np.reshape(vol, [np.prod(vol.shape[:3]), vol.shape[3]]) uchar_array = numpy_support.numpy_to_vtk(vol, deep=0) im.GetPointData().SetScalars(uchar_array) if affine is None: affine = np.eye(4) # Set the transform (identity if none given) transform = vtk.vtkTransform() transform_matrix = vtk.vtkMatrix4x4() transform_matrix.DeepCopy(( affine[0][0], affine[0][1], affine[0][2], affine[0][3], affine[1][0], affine[1][1], affine[1][2], affine[1][3], affine[2][0], affine[2][1], affine[2][2], affine[2][3], affine[3][0], affine[3][1], affine[3][2], affine[3][3])) transform.SetMatrix(transform_matrix) transform.Inverse() # Set the reslicing image_resliced = vtk.vtkImageReslice() set_input(image_resliced, im) image_resliced.SetResliceTransform(transform) image_resliced.AutoCropOutputOn() # Adding this will allow to support anisotropic voxels # and also gives the opportunity to slice per voxel coordinates RZS = affine[:3, :3] zooms = np.sqrt(np.sum(RZS * RZS, axis=0)) image_resliced.SetOutputSpacing(*zooms) image_resliced.SetInterpolationModeToLinear() image_resliced.Update() if nb_components == 1: if lookup_colormap is None: # Create a black/white lookup table. lut = colormap_lookup_table((0, 255), (0, 0), (0, 0), (0, 1)) else: lut = lookup_colormap x1, x2, y1, y2, z1, z2 = im.GetExtent() ex1, ex2, ey1, ey2, ez1, ez2 = image_resliced.GetOutput().GetExtent() class ImageActor(vtk.vtkImageActor): def input_connection(self, output): if vtk.VTK_MAJOR_VERSION <= 5: self.SetInput(output.GetOutput()) else: self.GetMapper().SetInputConnection(output.GetOutputPort()) self.output = output self.shape = (ex2 + 1, ey2 + 1, ez2 + 1) def display_extent(self, x1, x2, y1, y2, z1, z2): self.SetDisplayExtent(x1, x2, y1, y2, z1, z2) if vtk.VTK_MAJOR_VERSION > 5: self.Update() def display(self, x=None, y=None, z=None): if x is None and y is None and z is None: self.display_extent(ex1, ex2, ey1, ey2, ez2/2, ez2/2) if x is not None: self.display_extent(x, x, ey1, ey2, ez1, ez2) if y is not None: self.display_extent(ex1, ex2, y, y, ez1, ez2) if z is not None: self.display_extent(ex1, ex2, ey1, ey2, z, z) def opacity(self, value): if vtk.VTK_MAJOR_VERSION <= 5: self.SetOpacity(value) else: self.GetProperty().SetOpacity(value) def copy(self): im_actor = ImageActor() im_actor.input_connection(self.output) im_actor.SetDisplayExtent(*self.GetDisplayExtent()) im_actor.opacity(opacity) return im_actor image_actor = ImageActor() if nb_components == 1: plane_colors = vtk.vtkImageMapToColors() plane_colors.SetLookupTable(lut) plane_colors.SetInputConnection(image_resliced.GetOutputPort()) plane_colors.Update() image_actor.input_connection(plane_colors) else: image_actor.input_connection(image_resliced) image_actor.display() image_actor.opacity(opacity) if interpolation == 'nearest': image_actor.SetInterpolate(False) else: image_actor.SetInterpolate(True) if major_version >= 6: image_actor.GetMapper().BorderOn() return image_actor
def streamtube(lines, colors=None, opacity=1, linewidth=0.1, tube_sides=9, lod=True, lod_points=10 ** 4, lod_points_size=3, spline_subdiv=None, lookup_colormap=None): """ Uses streamtubes to visualize polylines Parameters ---------- lines : list list of N curves represented as 2D ndarrays colors : array (N, 3), list of arrays, tuple (3,), array (K,), None If None then a standard orientation colormap is used for every line. If one tuple of color is used. Then all streamlines will have the same colour. If an array (N, 3) is given, where N is equal to the number of lines. Then every line is coloured with a different RGB color. If a list of RGB arrays is given then every point of every line takes a different color. If an array (K, ) is given, where K is the number of points of all lines then these are considered as the values to be used by the colormap. If an array (L, ) is given, where L is the number of streamlines then these are considered as the values to be used by the colormap per streamline. If an array (X, Y, Z) or (X, Y, Z, 3) is given then the values for the colormap are interpolated automatically using trilinear interpolation. opacity : float Default is 1. linewidth : float Default is 0.01. tube_sides : int Default is 9. lod : bool Use vtkLODActor(level of detail) rather than vtkActor. Default is True. Level of detail actors do not render the full geometry when the frame rate is low. lod_points : int Number of points to be used when LOD is in effect. Default is 10000. lod_points_size : int Size of points when lod is in effect. Default is 3. spline_subdiv : int Number of splines subdivision to smooth streamtubes. Default is None. lookup_colormap : vtkLookupTable Add a default lookup table to the colormap. Default is None which calls :func:`dipy.viz.actor.colormap_lookup_table`. Examples -------- >>> import numpy as np >>> from dipy.viz import actor, window >>> ren = window.Renderer() >>> lines = [np.random.rand(10, 3), np.random.rand(20, 3)] >>> colors = np.random.rand(2, 3) >>> c = actor.streamtube(lines, colors) >>> ren.add(c) >>> #window.show(ren) Notes ----- Streamtubes can be heavy on GPU when loading many streamlines and therefore, you may experience slow rendering time depending on system GPU. A solution to this problem is to reduce the number of points in each streamline. In Dipy we provide an algorithm that will reduce the number of points on the straighter parts of the streamline but keep more points on the curvier parts. This can be used in the following way:: from dipy.tracking.distances import approx_polygon_track lines = [approx_polygon_track(line, 0.2) for line in lines] Alternatively we suggest using the ``line`` actor which is much more efficient. See Also -------- :func:``dipy.viz.actor.line`` """ # Poly data with lines and colors poly_data, is_colormap = lines_to_vtk_polydata(lines, colors) next_input = poly_data # Set Normals poly_normals = set_input(vtk.vtkPolyDataNormals(), next_input) poly_normals.ComputeCellNormalsOn() poly_normals.ComputePointNormalsOn() poly_normals.ConsistencyOn() poly_normals.AutoOrientNormalsOn() poly_normals.Update() next_input = poly_normals.GetOutputPort() # Spline interpolation if (spline_subdiv is not None) and (spline_subdiv > 0): spline_filter = set_input(vtk.vtkSplineFilter(), next_input) spline_filter.SetSubdivideToSpecified() spline_filter.SetNumberOfSubdivisions(spline_subdiv) spline_filter.Update() next_input = spline_filter.GetOutputPort() # Add thickness to the resulting lines tube_filter = set_input(vtk.vtkTubeFilter(), next_input) tube_filter.SetNumberOfSides(tube_sides) tube_filter.SetRadius(linewidth) # TODO using the line above we will be able to visualize # streamtubes of varying radius # tube_filter.SetVaryRadiusToVaryRadiusByScalar() tube_filter.CappingOn() tube_filter.Update() next_input = tube_filter.GetOutputPort() # Poly mapper poly_mapper = set_input(vtk.vtkPolyDataMapper(), next_input) poly_mapper.ScalarVisibilityOn() poly_mapper.SetScalarModeToUsePointFieldData() poly_mapper.SelectColorArray("Colors") poly_mapper.GlobalImmediateModeRenderingOn() poly_mapper.Update() # Color Scale with a lookup table if is_colormap: if lookup_colormap is None: lookup_colormap = colormap_lookup_table() poly_mapper.SetLookupTable(lookup_colormap) poly_mapper.UseLookupTableScalarRangeOn() poly_mapper.Update() # Set Actor if lod: actor = vtk.vtkLODActor() actor.SetNumberOfCloudPoints(lod_points) actor.GetProperty().SetPointSize(lod_points_size) else: actor = vtk.vtkActor() actor.SetMapper(poly_mapper) actor.GetProperty().SetAmbient(0.1) actor.GetProperty().SetDiffuse(0.15) actor.GetProperty().SetSpecular(0.05) actor.GetProperty().SetSpecularPower(6) actor.GetProperty().SetInterpolationToPhong() actor.GetProperty().BackfaceCullingOn() actor.GetProperty().SetOpacity(opacity) return actor
def line(lines, colors=None, opacity=1, linewidth=1, spline_subdiv=None, lod=True, lod_points=10**4, lod_points_size=3, lookup_colormap=None): """ Create an actor for one or more lines. Parameters ------------ lines : list of arrays colors : array (N, 3), list of arrays, tuple (3,), array (K,), None If None then a standard orientation colormap is used for every line. If one tuple of color is used. Then all streamlines will have the same colour. If an array (N, 3) is given, where N is equal to the number of lines. Then every line is coloured with a different RGB color. If a list of RGB arrays is given then every point of every line takes a different color. If an array (K, ) is given, where K is the number of points of all lines then these are considered as the values to be used by the colormap. If an array (L, ) is given, where L is the number of streamlines then these are considered as the values to be used by the colormap per streamline. If an array (X, Y, Z) or (X, Y, Z, 3) is given then the values for the colormap are interpolated automatically using trilinear interpolation. opacity : float, optional Default is 1. linewidth : float, optional Line thickness. Default is 1. spline_subdiv : int, optional Number of splines subdivision to smooth streamtubes. Default is None which means no subdivision. lod : bool Use vtkLODActor(level of detail) rather than vtkActor. Default is True. Level of detail actors do not render the full geometry when the frame rate is low. lod_points : int Number of points to be used when LOD is in effect. Default is 10000. lod_points_size : int Size of points when lod is in effect. Default is 3. lookup_colormap : bool, optional Add a default lookup table to the colormap. Default is None which calls :func:`dipy.viz.actor.colormap_lookup_table`. Returns ---------- v : vtkActor or vtkLODActor object Line. Examples ---------- >>> from dipy.viz import actor, window >>> ren = window.Renderer() >>> lines = [np.random.rand(10, 3), np.random.rand(20, 3)] >>> colors = np.random.rand(2, 3) >>> c = actor.line(lines, colors) >>> ren.add(c) >>> #window.show(ren) """ # Poly data with lines and colors poly_data, is_colormap = lines_to_vtk_polydata(lines, colors) next_input = poly_data # use spline interpolation if (spline_subdiv is not None) and (spline_subdiv > 0): spline_filter = set_input(vtk.vtkSplineFilter(), next_input) spline_filter.SetSubdivideToSpecified() spline_filter.SetNumberOfSubdivisions(spline_subdiv) spline_filter.Update() next_input = spline_filter.GetOutputPort() poly_mapper = set_input(vtk.vtkPolyDataMapper(), next_input) poly_mapper.ScalarVisibilityOn() poly_mapper.SetScalarModeToUsePointFieldData() poly_mapper.SelectColorArray("Colors") poly_mapper.Update() # Color Scale with a lookup table if is_colormap: if lookup_colormap is None: lookup_colormap = colormap_lookup_table() poly_mapper.SetLookupTable(lookup_colormap) poly_mapper.UseLookupTableScalarRangeOn() poly_mapper.Update() # Set Actor if lod: actor = vtk.vtkLODActor() actor.SetNumberOfCloudPoints(lod_points) actor.GetProperty().SetPointSize(lod_points_size) else: actor = vtk.vtkActor() # actor = vtk.vtkActor() actor.SetMapper(poly_mapper) actor.GetProperty().SetLineWidth(linewidth) actor.GetProperty().SetOpacity(opacity) return actor
def slicer(data, affine=None, value_range=None, opacity=1., lookup_colormap=None, interpolation='linear'): """ Cuts 3D scalar or rgb volumes into 2D images Parameters ---------- data : array, shape (X, Y, Z) or (X, Y, Z, 3) A grayscale or rgb 4D volume as a numpy array. affine : array, shape (4, 4) Grid to space (usually RAS 1mm) transformation matrix. Default is None. If None then the identity matrix is used. value_range : None or tuple (2,) If None then the values will be interpolated from (data.min(), data.max()) to (0, 255). Otherwise from (value_range[0], value_range[1]) to (0, 255). opacity : float Opacity of 0 means completely transparent and 1 completely visible. lookup_colormap : vtkLookupTable If None (default) then a grayscale map is created. interpolation : string If 'linear' (default) then linear interpolation is used on the final texture mapping. If 'nearest' then nearest neighbor interpolation is used on the final texture mapping. Returns ------- image_actor : ImageActor An object that is capable of displaying different parts of the volume as slices. The key method of this object is ``display_extent`` where one can input grid coordinates and display the slice in space (or grid) coordinates as calculated by the affine parameter. """ if data.ndim != 3: if data.ndim == 4: if data.shape[3] != 3: raise ValueError('Only RGB 3D arrays are currently supported.') else: nb_components = 3 else: raise ValueError('Only 3D arrays are currently supported.') else: nb_components = 1 if value_range is None: vol = np.interp(data, xp=[data.min(), data.max()], fp=[0, 255]) else: vol = np.interp(data, xp=[value_range[0], value_range[1]], fp=[0, 255]) vol = vol.astype('uint8') im = vtk.vtkImageData() if major_version <= 5: im.SetScalarTypeToUnsignedChar() I, J, K = vol.shape[:3] im.SetDimensions(I, J, K) voxsz = (1., 1., 1.) # im.SetOrigin(0,0,0) im.SetSpacing(voxsz[2], voxsz[0], voxsz[1]) if major_version <= 5: im.AllocateScalars() im.SetNumberOfScalarComponents(nb_components) else: im.AllocateScalars(vtk.VTK_UNSIGNED_CHAR, nb_components) # copy data # what I do below is the same as what is commented here but much faster # for index in ndindex(vol.shape): # i, j, k = index # im.SetScalarComponentFromFloat(i, j, k, 0, vol[i, j, k]) vol = np.swapaxes(vol, 0, 2) vol = np.ascontiguousarray(vol) if nb_components == 1: vol = vol.ravel() else: vol = np.reshape(vol, [np.prod(vol.shape[:3]), vol.shape[3]]) uchar_array = numpy_support.numpy_to_vtk(vol, deep=0) im.GetPointData().SetScalars(uchar_array) if affine is None: affine = np.eye(4) # Set the transform (identity if none given) transform = vtk.vtkTransform() transform_matrix = vtk.vtkMatrix4x4() transform_matrix.DeepCopy( (affine[0][0], affine[0][1], affine[0][2], affine[0][3], affine[1][0], affine[1][1], affine[1][2], affine[1][3], affine[2][0], affine[2][1], affine[2][2], affine[2][3], affine[3][0], affine[3][1], affine[3][2], affine[3][3])) transform.SetMatrix(transform_matrix) transform.Inverse() # Set the reslicing image_resliced = vtk.vtkImageReslice() set_input(image_resliced, im) image_resliced.SetResliceTransform(transform) image_resliced.AutoCropOutputOn() # Adding this will allow to support anisotropic voxels # and also gives the opportunity to slice per voxel coordinates RZS = affine[:3, :3] zooms = np.sqrt(np.sum(RZS * RZS, axis=0)) image_resliced.SetOutputSpacing(*zooms) image_resliced.SetInterpolationModeToLinear() image_resliced.Update() if nb_components == 1: if lookup_colormap is None: # Create a black/white lookup table. lut = colormap_lookup_table((0, 255), (0, 0), (0, 0), (0, 1)) else: lut = lookup_colormap x1, x2, y1, y2, z1, z2 = im.GetExtent() ex1, ex2, ey1, ey2, ez1, ez2 = image_resliced.GetOutput().GetExtent() class ImageActor(vtk.vtkImageActor): def input_connection(self, output): if vtk.VTK_MAJOR_VERSION <= 5: self.SetInput(output.GetOutput()) else: self.GetMapper().SetInputConnection(output.GetOutputPort()) self.output = output self.shape = (ex2 + 1, ey2 + 1, ez2 + 1) def display_extent(self, x1, x2, y1, y2, z1, z2): self.SetDisplayExtent(x1, x2, y1, y2, z1, z2) if vtk.VTK_MAJOR_VERSION > 5: self.Update() def display(self, x=None, y=None, z=None): if x is None and y is None and z is None: self.display_extent(ex1, ex2, ey1, ey2, ez2 // 2, ez2 // 2) if x is not None: self.display_extent(x, x, ey1, ey2, ez1, ez2) if y is not None: self.display_extent(ex1, ex2, y, y, ez1, ez2) if z is not None: self.display_extent(ex1, ex2, ey1, ey2, z, z) def opacity(self, value): if vtk.VTK_MAJOR_VERSION <= 5: self.SetOpacity(value) else: self.GetProperty().SetOpacity(value) def copy(self): im_actor = ImageActor() im_actor.input_connection(self.output) im_actor.SetDisplayExtent(*self.GetDisplayExtent()) im_actor.opacity(opacity) if interpolation == 'nearest': im_actor.SetInterpolate(False) else: im_actor.SetInterpolate(True) if major_version >= 6: im_actor.GetMapper().BorderOn() return im_actor image_actor = ImageActor() if nb_components == 1: plane_colors = vtk.vtkImageMapToColors() plane_colors.SetLookupTable(lut) plane_colors.SetInputConnection(image_resliced.GetOutputPort()) plane_colors.Update() image_actor.input_connection(plane_colors) else: image_actor.input_connection(image_resliced) image_actor.display() image_actor.opacity(opacity) if interpolation == 'nearest': image_actor.SetInterpolate(False) else: image_actor.SetInterpolate(True) if major_version >= 6: image_actor.GetMapper().BorderOn() return image_actor
def streamtube(lines, colors=None, opacity=1, linewidth=0.1, tube_sides=9, lod=True, lod_points=10**4, lod_points_size=3, spline_subdiv=None, lookup_colormap=None): """ Uses streamtubes to visualize polylines Parameters ---------- lines : list list of N curves represented as 2D ndarrays colors : array (N, 3), list of arrays, tuple (3,), array (K,), None If None then a standard orientation colormap is used for every line. If one tuple of color is used. Then all streamlines will have the same colour. If an array (N, 3) is given, where N is equal to the number of lines. Then every line is coloured with a different RGB color. If a list of RGB arrays is given then every point of every line takes a different color. If an array (K, ) is given, where K is the number of points of all lines then these are considered as the values to be used by the colormap. If an array (L, ) is given, where L is the number of streamlines then these are considered as the values to be used by the colormap per streamline. If an array (X, Y, Z) or (X, Y, Z, 3) is given then the values for the colormap are interpolated automatically using trilinear interpolation. opacity : float Default is 1. linewidth : float Default is 0.01. tube_sides : int Default is 9. lod : bool Use vtkLODActor(level of detail) rather than vtkActor. Default is True. Level of detail actors do not render the full geometry when the frame rate is low. lod_points : int Number of points to be used when LOD is in effect. Default is 10000. lod_points_size : int Size of points when lod is in effect. Default is 3. spline_subdiv : int Number of splines subdivision to smooth streamtubes. Default is None. lookup_colormap : vtkLookupTable Add a default lookup table to the colormap. Default is None which calls :func:`dipy.viz.actor.colormap_lookup_table`. Examples -------- >>> import numpy as np >>> from dipy.viz import actor, window >>> ren = window.Renderer() >>> lines = [np.random.rand(10, 3), np.random.rand(20, 3)] >>> colors = np.random.rand(2, 3) >>> c = actor.streamtube(lines, colors) >>> ren.add(c) >>> #window.show(ren) Notes ----- Streamtubes can be heavy on GPU when loading many streamlines and therefore, you may experience slow rendering time depending on system GPU. A solution to this problem is to reduce the number of points in each streamline. In Dipy we provide an algorithm that will reduce the number of points on the straighter parts of the streamline but keep more points on the curvier parts. This can be used in the following way:: from dipy.tracking.distances import approx_polygon_track lines = [approx_polygon_track(line, 0.2) for line in lines] Alternatively we suggest using the ``line`` actor which is much more efficient. See Also -------- :func:`dipy.viz.actor.line` """ # Poly data with lines and colors poly_data, is_colormap = lines_to_vtk_polydata(lines, colors) next_input = poly_data # Set Normals poly_normals = set_input(vtk.vtkPolyDataNormals(), next_input) poly_normals.ComputeCellNormalsOn() poly_normals.ComputePointNormalsOn() poly_normals.ConsistencyOn() poly_normals.AutoOrientNormalsOn() poly_normals.Update() next_input = poly_normals.GetOutputPort() # Spline interpolation if (spline_subdiv is not None) and (spline_subdiv > 0): spline_filter = set_input(vtk.vtkSplineFilter(), next_input) spline_filter.SetSubdivideToSpecified() spline_filter.SetNumberOfSubdivisions(spline_subdiv) spline_filter.Update() next_input = spline_filter.GetOutputPort() # Add thickness to the resulting lines tube_filter = set_input(vtk.vtkTubeFilter(), next_input) tube_filter.SetNumberOfSides(tube_sides) tube_filter.SetRadius(linewidth) # TODO using the line above we will be able to visualize # streamtubes of varying radius # tube_filter.SetVaryRadiusToVaryRadiusByScalar() tube_filter.CappingOn() tube_filter.Update() next_input = tube_filter.GetOutputPort() # Poly mapper poly_mapper = set_input(vtk.vtkPolyDataMapper(), next_input) poly_mapper.ScalarVisibilityOn() poly_mapper.SetScalarModeToUsePointFieldData() poly_mapper.SelectColorArray("Colors") poly_mapper.GlobalImmediateModeRenderingOn() poly_mapper.Update() # Color Scale with a lookup table if is_colormap: if lookup_colormap is None: lookup_colormap = colormap_lookup_table() poly_mapper.SetLookupTable(lookup_colormap) poly_mapper.UseLookupTableScalarRangeOn() poly_mapper.Update() # Set Actor if lod: actor = vtk.vtkLODActor() actor.SetNumberOfCloudPoints(lod_points) actor.GetProperty().SetPointSize(lod_points_size) else: actor = vtk.vtkActor() actor.SetMapper(poly_mapper) actor.GetProperty().SetAmbient(0.1) actor.GetProperty().SetDiffuse(0.15) actor.GetProperty().SetSpecular(0.05) actor.GetProperty().SetSpecularPower(6) actor.GetProperty().SetInterpolationToPhong() actor.GetProperty().BackfaceCullingOn() actor.GetProperty().SetOpacity(opacity) return actor