Package 'threeBrain'

Title: Your Advanced 3D Brain Visualization
Description: A fast, interactive cross-platform, and easy to share 'WebGL'-based 3D brain viewer that visualizes 'FreeSurfer' and/or 'AFNI/SUMA' surfaces. The viewer widget can be either standalone or embedded into 'R-shiny' applications. The standalone version only require a web browser with 'WebGL2' support (for example, 'Chrome', 'Firefox', 'Safari'), and can be inserted into any websites. The 'R-shiny' support allows the 3D viewer to be dynamically generated from reactive user inputs. Please check the publication by Wang, Magnotti, Zhang, and Beauchamp (2023, <doi:10.1523/ENEURO.0328-23.2023>) for electrode localization. This viewer has been fully adopted by 'RAVE' <https://openwetware.org/wiki/RAVE>, an interactive toolbox to analyze 'iEEG' data by Magnotti, Wang, and Beauchamp (2020, <doi:10.1016/j.neuroimage.2020.117341>). Please check 'citation("threeBrain")' for details.
Authors: Zhengjia Wang [aut, cre, cph], John Magnotti [ctb, res], Xiang Zhang [ctb, res], Brian Metzger [res], Elizabeth Nesbitt [res], Meng Li [ths], Michael Beauchamp [ths, ctb, dtc]
Maintainer: Zhengjia Wang <[email protected]>
License: MPL-2.0
Version: 1.2.0
Built: 2024-11-08 10:31:10 UTC
Source: CRAN

Help Index

R6 Class - Abstract Class of Geometries

Description

R6 Class - Abstract Class of Geometries

Author(s)

Zhengjia Wang

A geometry that renders nothing

Description

This is mainly used when you want to upload group data only

Shiny Proxy for Viewer

Description

Shiny Proxy for Viewer

Usage

brain_proxy(outputId, session = shiny::getDefaultReactiveDomain())

Arguments

outputId

shiny output ID
session

shiny session, default is current session (see domains)

Value

R6 class ViewerProxy

Setup Package, Install Environment

Description

Setup Package, Install Environment

Usage

brain_setup(continued = FALSE, show_example = TRUE, ...)

Arguments

continued

logical, there are two phases of setting up environment. You probably need to restart R session after the first phase and continue setting up.
show_example

whether to show example of 'N27' subject at the end.
...

ignored

Author(s)

Zhengjia Wang

Calculate rotation matrix from non-zero vectors

Description

Calculate rotation matrix from non-zero vectors

Usage

calculate_rotation(vec_from, vec_to)

Arguments

vec_from

original vector, length of 3
vec_to

vector after rotation, length of 3

Value

A four-by-four transform matrix

Function to check whether 'FreeSurfer' folder has everything we need

Description

Function to check whether 'FreeSurfer' folder has everything we need

Usage

check_freesurfer_path(
  fs_subject_folder,
  autoinstall_template = FALSE,
  return_path = FALSE,
  check_volume = FALSE,
  check_surface = FALSE
)

Arguments

fs_subject_folder

character, path to 'fs' project directory or 'RAVE' subject directory
autoinstall_template

logical, whether 'N27' brain should be installed if missing
return_path

logical, whether to return 'FreeSurfer' path
check_volume

logical, whether to check volume data
check_surface

logical, whether to check surface data (not implemented yet)

Value

logical whether the directory is valid or, if return_path is true, return 'FreeSurfer' path

Conform imaging data in 'FreeSurfer' way

Description

Reproduces conform algorithm used by 'FreeSurfer' to conform 'NIfTI' and 'MGH' images.

Usage

conform_volume(x, save_to, dim = c(256, 256, 256))

Arguments

x

path to the image file
save_to

path where the conformed image will be saved, must ends with '.mgz'
dim

positive integers of length three, the conformed dimension; by default 'FreeSurfer' conform images to 1mm volume cube with 256x256x256 dimension

Value

Nothing; the result will be save to save_to

Create a geometry group containing multiple geometries

Description

Create a geometry group containing multiple geometries

Usage

create_group(name, position = c(0, 0, 0), layer = 1)

Arguments

name

string, name of the geometry
position

x,y,z location of the group
layer

layer of the group. reserved

Details

A geometry group is a container of multiple geometries. The geometries within the same group share the same shift and rotations (see example 1). In ECoG/iEEG world, you might have 'MRI', 'CT', 'FreeSurfer' that have different orientations. For example, if you want to align MRI to FreeSurfer, Instead of calculating the position of each geometries, you can just put all MRI components into a group, and then set transform of this group, making the group aligned to FreeSurfer.

GeomGroup also can be used to store large data. To generate 3D viewer, 'threeBrain' needs to dynamically serialize data into JSON format, which can be read by browsers. However, a FreeSurfer brain might be ~30 MB. This is a very large size and might take ~5 seconds to serialize. To solve this problem, GeomGroup supports cache in its 'set_group_data' method. This method supports caching static serialized data into a JSON file, and allows the files to be loaded as static data objects. By "static", I mean the data is not supposed to be dynamic, and it should be "read-only". In JavaScript code, I also optimized such that you don't need to load these large datasets repeatedly. And this allows you to load multiple subjects' brain in a short time.

Value

a GeomGroup instance

Author(s)

Zhengjia Wang

Examples

# Example 1: relative position

# create group
g = create_group('Group A')

# create two spheres at 10,0,0, but s2 is relative to group A
s1 = geom_sphere('Sphere 1', radius = 2, position = c(10,0,0))
s2 = geom_sphere('Sphere 2', radius = 2, position = c(10,0,0), group = g)

# set transform (rotation)
g$set_transform(matrix(c(
  0,1,0,0,
  1,0,0,0,
  0,0,1,0,
  0,0,0,1
), byrow = TRUE, ncol = 4))

# global position for s2 is 0,10,0
if( interactive() ) { threejs_brain(s1, s2) }

# Example 2: cache

## Not run: 

# download N27 brain
# Make sure you have N27 brain downloaded to `default_template_directory()`
# download_N27()

template_dir <- default_template_directory()

dat = freesurferformats::read.fs.surface(
  file.path(template_dir, 'N27/surf/lh.pial')
)
vertex = dat$vertices[,1:3]
face = dat$faces[,1:3]

# 1. dynamically serialize
mesh = geom_freemesh('lh', vertex = vertex, face = face, layer = 1)

# 2. cache
# Create group, all geometries in this group are relatively positioned
tmp_file = tempfile()
mesh = geom_freemesh('Left Hemisphere cached', vertex = vertex,
                     face = face, cache_file = tmp_file)


## End(Not run)

Calculate cross-product of two vectors in '3D'

Description

Calculate cross-product of two vectors in '3D'

Usage

cross_prod(x, y)

Arguments

x, y

3-dimensional vectors

Value

A '3D' vector that is the cross-product of x and y

R6 Class - Generate Data Cube Geometry

Description

R6 Class - Generate Data Cube Geometry

Author(s)

Zhengjia Wang

R6 Class - Generate Data Cube Geometry via 3D Volume Texture

Description

R6 Class - Generate Data Cube Geometry via 3D Volume Texture

Author(s)

Zhengjia Wang

Default Directory to Store Template Brain

Description

Default Directory to Store Template Brain

Usage

default_template_directory(check = FALSE)

Arguments

check

logical, check if the folder is missing, is so, create one. This option ensures the folder is always created.

Details

When threeBrain.template_dir is not set or invalid, the function checks 'RAVE' (R Analysis and Visualization for 'iEEG', https://openwetware.org/wiki/RAVE) folder at home directory. If this folder is missing, then returns results from R_user_dir('threeBrain', 'data'). To override the default behavior, use options(threeBrain.template_dir=...).

Value

A directory path where template brain is stored at; see also download_N27

Examples

default_template_directory()

R6 Class - Generate Geometry from Vertices and Face Indices

Description

R6 Class - Generate Geometry from Vertices and Face Indices

Read 'FreeSurfer' surface and volume files

Description

Read 'FreeSurfer' surface and volume files

Usage

freesurfer_brain(
  fs_subject_folder,
  subject_name,
  additional_surfaces = NULL,
  aligned_ct = NULL,
  use_cache = TRUE,
  use_141 = getOption("threeBrain.use141", TRUE)
)

freesurfer_brain2(
  fs_subject_folder,
  subject_name,
  volume_types = "t1",
  surface_types = "pial",
  curvature = "sulc",
  atlas_types = c("aparc+aseg", "aparc.a2009s+aseg", "aparc.DKTatlas+aseg"),
  ct_path = NULL,
  use_cache = TRUE,
  use_141 = getOption("threeBrain.use141", TRUE),
  ...
)

Arguments

fs_subject_folder

character, 'FreeSurfer' subject folder, or 'RAVE' subject folder
subject_name

character, subject code to display with only letters and digits
additional_surfaces

character array, additional surface types to load, such as 'white', 'smoothwm'
aligned_ct

character, path to 'ct_aligned_mri.nii.gz', used for electrode localization
use_cache

logical, whether to use cached 'json' files or from raw 'FreeSurfer' files
use_141

logical, whether to use standard 141 brain for surface file, default is getOption('threeBrain.use141', TRUE)
volume_types

volume types, right now only support T1 image
surface_types

surface types to load
curvature

curvature data. Only support "sulc" for current version
atlas_types

atlas types to be loaded, choices are 'aparc+aseg', 'aparc.a2009s+aseg', 'aparc.DKTatlas+aseg', 'aseg'
ct_path

an aligned CT file in 'Nifti' format
...

ignored

Details

This function is under FreeSurfer license. 1. Volumes: 3D viewer uses 'mri/T1.mgz' from 'FreeSurfer' to show the volume information. 'T1.mgz' results from step 1 to 5 in 'FreeSurfer' command 'recon-all -autorecon1', which aligns the original 'DICOM' image to 'RAS' coordinate system, resamples to volume with 256x256x256 voxels (tri-linear by default, check https://surfer.nmr.mgh.harvard.edu/fswiki/recon-all for more information).

2. Surface: There are two options for surface files. The first choice is using 'std.141' brain generated by 'AFNI/SUMA'. This surface file re-calculates vertices from standard 141 space, which averages the "surface" of 141 subjects. If you want to map surface electrodes across different subjects, you might want to consider this case as it's especially designed for surface mapping. However, you'll need 'AFNI/SUMA' installed to generate the surface file. The details can be found via https://openwetware.org/wiki/Beauchamp:CorticalSurfaceHCP, and the 'AFNI/SUMA' command related is 'SurfToSurf'. Please generate the files to '[FREESURFER SUBJECT DIR]/SUMA/'. The file name follows the convention of 'std.141.[lr]h.[SURFACE TYPE].[POSTFIX]', where 'lh' means left hemisphere and 'rh' means right hemisphere; 'SURFACE TYPE' can be 'pial', 'white', 'smoothwm', and 'POSTFIX' can be 'asc', 'gii'. If multiple files for the same surface type exists, the search order will be 'asc > gii'. The other option is to use mesh files directly from 'FreeSurfer' output located at '[FREESURFER SUBJECT DIR]/surf'. If you want to use these surface, make sure they are converted to 'asc' or 'gii' format.

3. Electrode registration and transforms This package provides two ways to map electrodes to standard space. For surface electrodes, if standard 141 brain is provided, then the first option is to snap electrodes to the nearest vertices in subject space. The key is the vertex number matches across different subjects, hence the location of corresponding vertices at template brain are the mapped electrode coordinates. If standard 141 brain is missing, or the electrode type is 'stereo EEG', then the second option is volume mapping. The idea is to map electrodes to 'MNI305' brain. The details can be found at https://surfer.nmr.mgh.harvard.edu/fswiki/CoordinateSystems. To perform volume mapping, we need 'FreeSurfer' folder 'mri/transforms'. Currently, only linear 'Talairach' transform matrix is supported (located at 'talairach.xfm').

4. Coordinates The 3D viewer in this package uses the center of volume as the origin (0, 0, 0).

Author(s)

Zhengjia Wang

Examples

## Not run: 
# Please run `download_N27()` if `N27` is not at `default_template_directory()`

# Import from `FreeSurfer` subject folder
brain = threeBrain::freesurfer_brain(
  fs_subject_folder = file.path(default_template_directory(), 'N27'),
  subject_name = 'N27',
  additional_surfaces = c('white', 'smoothwm')
)

# Visualize. Alternatively, you can use brain$plot(...)
plot( brain )

## End(Not run)

Query the 'FreeSurfer' labels

Description

Query the 'FreeSurfer' labels

Usage

freesurfer_lut

Format

An object of class list of length 3.

Details

The 'FreeSurfer' atlases use https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/AnatomicalROI/FreeSurferColorLUT look-up table to query indexes. The 'threeBrain' electrode localization also uses this table to export the 'FSLabel' from electrode. If volume type is set to 'aparc_aseg', then please also use this table to filter.

Examples

freesurfer_lut$from_key(0:10)

freesurfer_lut$get_key("ctx-lh-supramarginal")

Generate smooth envelope around surface

Description

Alternative to 'Matlab' version of 'pial-outer-smoothed', use this function along with fill_surface.

Usage

generate_smooth_envelope(
  surface_path,
  save_as = NULL,
  inflate = 3,
  verbose = TRUE,
  save_format = c("auto", "bin", "asc", "vtk", "ply", "off", "obj", "gii", "mz3", "byu")
)

Arguments

surface_path

path to '*h.pial' surface in the 'FreeSurfer' folder, or a 3-dimensional mesh, see read.fs.surface
save_as

save final envelope to path, or NULL for dry-run
inflate

number of 'voxels' to inflate before fitting envelope; must be a non-negative integer
verbose

whether to verbose the progress; default is true
save_format

format of saved file when save_as is not NULL; see format argument in function write.fs.surface

Value

A 3-dimensional mesh that contains vertices and face indices, the result is also saved to save_as is specified.

Examples

if(interactive() &&
   file.exists(file.path(default_template_directory(), "N27"))) {

library(threeBrain)

fs_path <- file.path(default_template_directory(), "N27")

# lh.pial-outer-smoothed
lh_pial <- file.path(fs_path, "surf", "lh.pial")
save_as <- file.path(fs_path, "surf", "lh.pial-outer-smoothed")
generate_smooth_envelope(lh_pial, save_as)

# rh.pial-outer-smoothed
rh_pial <- file.path(fs_path, "surf", "rh.pial")
save_as <- file.path(fs_path, "surf", "rh.pial-outer-smoothed")
generate_smooth_envelope(rh_pial, save_as)

brain <- threeBrain(
  path = fs_path, subject_code = "N27",
  surface_types = 'pial-outer-smoothed'
)
brain$plot(controllers = list(
  "Surface Type" = 'pial-outer-smoothed'
))

}

Approximate 'sub-cortical' surfaces from 'parcellation'

Description

Superseded by volume_to_surf. Please do not use this function.

Usage

generate_subcortical_surface(
  atlas,
  index,
  save_prefix = NULL,
  label = NULL,
  IJK2RAS = NULL,
  grow = 1,
  remesh = TRUE,
  smooth = TRUE,
  smooth_delta = 3,
  ...
)

Arguments

atlas

path to imaging 'parcellation', can be 'nii' or 'mgz' formats
index

'parcellation' index, see 'FreeSurfer' look-up table
save_prefix

parent folder to save the resulting surface
label

character label or name of the 'sub-cortical' structure, usually automatically derived from index
IJK2RAS

an 'Affine' matrix from 'voxel' index to 'tkrRAS', usually automatically derived from atlas
grow

amount to grow (dilate) before generating mesh
remesh, smooth, smooth_delta, ...

passed to mesh_from_volume

Value

A surface mesh, containing 'atlas' index, label, surface nodes and face indices.

Creates any mesh geometry given vertices and face indices

Description

Creates any mesh geometry given vertices and face indices

Usage

geom_freemesh(
  name,
  vertex = NULL,
  face = NULL,
  position = c(0, 0, 0),
  layer = 1,
  cache_file = NULL,
  group = NULL
)

Arguments

name

unique string in a scene to tell apart from different objects
vertex

position of each vertices (3 columns)
face

face indices indicating which 3 vertices to be linked (3 columns)
position

x,y,z location of the geometry
layer

visibility of the geometry, used when there are multiple cameras 1 is visible for all cameras
cache_file

cache vertex and face data into group
group

a GeomGroup object, if null, then the group will be generated automatically

Details

When generating a free mesh internally, a group must be specified, therefore if group is NULL here, then a group will be generated. However, it's always recommended to pass a group to the free mesh.

Author(s)

Zhengjia Wang

Examples

## Not run: 
# Make sure you have N27 brain downloaded to `default_template_directory()`
# threeBrain::download_N27()

n27_dir = file.path(default_template_directory(), "N27")
surf_type = 'pial'

# Locate mesh files
lh = read_fs_asc(file.path(n27_dir, sprintf('surf/lh.%s.asc', surf_type)))
rh = read_fs_asc(file.path(n27_dir, sprintf('surf/rh.%s.asc', surf_type)))

# Create groups
group = create_group(name = sprintf('Surface - %s (N27)', surf_type))

# create mesh
lh_mesh = geom_freemesh(
  name = sprintf('FreeSurfer Left Hemisphere - %s (N27)', surf_type),
  vertex = lh$vertices[,1:3],
  face = lh$faces[,1:3],
  group = group
)
rh_mesh = geom_freemesh(
  name = sprintf('FreeSurfer Right Hemisphere - %s (N27)', surf_type),
  vertex = rh$vertices[,1:3],
  face = rh$faces[,1:3],
  group = group
)


# Render
if( interactive() ) { threejs_brain(lh_mesh, rh_mesh) }




## End(Not run)

Create sphere geometry

Description

Create sphere geometry

Usage

geom_sphere(
  name,
  radius,
  position = c(0, 0, 0),
  layer = 1,
  group = NULL,
  value = NULL,
  time_stamp = NULL
)

Arguments

name

unique string in a scene to tell apart from different objects
radius

size of sphere
position

x,y,z location of the sphere
layer

visibility of the geometry, used when there are multiple cameras 1 is visible for all cameras
group

a GeomGroup object
value, time_stamp

color of the sphere, used for animation/color rendering

Author(s)

Zhengjia Wang

Examples

# Create a sphere with animation
g = lapply(1:10, function(ii){
  v = rep(ii, 10)
  v[1:ii] = 1:ii
  geom_sphere(paste0('s', ii), ii, value = v, position = c(11 * ii, 0,0), time_stamp = (1:10)/10)
})
if( interactive() ) { threejs_brain(.list = g) }

R6 Class - Generate Group of Geometries

Description

R6 Class - Generate Group of Geometries

Author(s)

Zhengjia Wang

Function to read digest header

Description

Function to read digest header

Usage

get_digest_header(file, key, if_error = NULL, .list = NULL)

Arguments

file

file path to a 'JSON' file
key

character, key to extract
if_error

value to return if key not found or read error occurs
.list

alternative list to supply if file is missing

Get 'voxel' to world matrix

Description

Get 'voxel' to world matrix

Usage

get_ijk2ras(x, type = c("scanner", "tkr"))

Arguments

x

path to imaging files
type

world space type; choices are 'scanner' (same as 'sform' or 'qform' in) or 'NIfTI' file headers; or 'tkr' (used to shared surface nodes)

Value

A four by four matrix

Import from 'FreeSurfer' and create 'JSON' cache for 3D viewer

Description

Import from 'FreeSurfer' and create 'JSON' cache for 3D viewer

Usage

import_from_freesurfer(fs_path, subject_name, quiet = FALSE)

Arguments

fs_path

'FreeSurfer' subject directory
subject_name

subject code
quiet

whether to suppress message or not

Value

None.

Import 'FreeSurfer' or 'SUMA' files into the viewer structure

Description

Import 'T1-MRI', surface files, curvature/'sulcus', atlas, and 'Talairach' transform matrix into 'json' format. These functions are not intended to be called directly, use import_from_freesurfer instead.

Usage

import_fs(
  subject_name,
  fs_path,
  quiet = FALSE,
  dtype = c("T1", "surface", "curv", "atlas_volume", "atlas_surface", "xform"),
  sub_type = NULL,
  hemisphere = c("l", "r"),
  ...
)

import_suma(
  subject_name,
  fs_path,
  quiet = FALSE,
  dtype = c("T1", "surface", "curv", "atlas_volume", "atlas_surface", "xform"),
  sub_type = NULL,
  hemisphere = c("l", "r"),
  ...
)

Arguments

subject_name

character, subject code
fs_path

path to 'FreeSurfer' folder
quiet, ...

passed from or to other methods.
dtype

data type to import, choices are 'T1', 'surface', 'curv', 'atlas_volume', 'atlas_surface', 'xform'
sub_type

detailed files to import. 'atlas_surface' is not supported for now
hemisphere

which hemisphere to import, ignored when dtype is in 'T1', 'atlas_volume', 'atlas_surface', 'xform'.

Value

logical, TRUE if the file is or has been cached, or FALSE if the file is missing.

R6 Class - Generate Line Segments

Description

R6 Class - Generate Line Segments

Author(s)

Zhengjia Wang

List or load all electrode prototypes

Description

List all built-in and user-customized electrode prototypes. User paths will be searched first, if multiple prototype configuration files are found for the same type.

Usage

list_electrode_prototypes()

load_prototype(type)

Arguments

type

electrode type, character

Value

list_electrode_prototypes returns a named list, names are the prototype types and values are the prototype configuration paths; load_prototype returns the prototype instance if type exists, or throw an error.

Examples

availables <- list_electrode_prototypes()
if( "sEEG-16" %in% names(availables) ) {
  proto <- load_prototype( "sEEG-16" )

  print(proto, details = FALSE)
}

Launch a 'shiny' application to localize electrodes

Description

If 'RAVE' has been installed, please use 'RAVE' modules. This function is purely for demonstration purposes.

Usage

localization_module(
  subject_code,
  fs_path,
  ct_path = NULL,
  surfaces = "pial",
  use_141 = TRUE,
  shiny_options = list(launch.browser = TRUE),
  save_path = tempfile(pattern = "electrode", fileext = ".csv"),
  ...,
  control_presets = NULL,
  side_display = FALSE,
  controllers = list()
)

Arguments

subject_code

subject code
fs_path

the subject's 'FreeSurfer' path
ct_path

the file path of 'CT' scans that have already been aligned to 'T1'; must be in 'NIFTI' format
surfaces

which surfaces to load
use_141

whether to try 'SUMA' standard 141 surface; default is true
shiny_options

shiny application options; see options in shinyApp
save_path

a temporary file where the electrode table should be cached; this file will be used to keep track of changes in case the application is crashed or shutdown
...

other parameters to pass into freesurfer_brain2
control_presets, side_display, controllers

passed to threejs_brain

Value

A list of 'ui' elements, 'server' function, and a stand-alone 'app'

Examples

# This example require N27 template brain to be installed
# see `?download_N27` for details

# using N27 to localize
fs_path <- file.path(default_template_directory(), "N27")
if(interactive() && dir.exists(fs_path)){
  module <- localization_module("N27", fs_path)

  print(module$app)
}

Create Multi-subject Template

Description

Create Multi-subject Template

Usage

merge_brain(
  ...,
  .list = NULL,
  template_surface_types = NULL,
  template_subject = unname(getOption("threeBrain.template_subject", "N27")),
  template_dir = default_template_directory()
)

Arguments

..., .list

Brain2 objects
template_surface_types

which template surface types to load, default is auto-guess
template_subject

character, subject code to be treated as template, default is 'N27'
template_dir

the parent directory where template subject is stored in

Author(s)

Zhengjia Wang

Create or load new electrode prototype from existing configurations

Description

Create or load new electrode prototype from existing configurations

Usage

new_electrode_prototype(base_prototype, modifier = NULL)

Arguments

base_prototype

base prototype, this can be a string of prototype type (see list_electrode_prototypes), path to the prototype configuration file, configuration in 'json' format, or an electrode prototype instance
modifier

internally used

Value

An electrode prototype instance

Examples

available_prototypes <- list_electrode_prototypes()
if("Precision33x31" %in% names(available_prototypes)) {

  # Load by type name
  new_electrode_prototype("Precision33x31")

  # load by path
  path <- available_prototypes[["Precision33x31"]]
  new_electrode_prototype(path)

  # load by json string
  json <- readLines(path)
  new_electrode_prototype(json)

}

Plot slices of volume

Description

Plot slices of volume

Usage

plot_slices(
  volume,
  overlays = NULL,
  transform = NULL,
  positions = NULL,
  zoom = 1,
  pixel_width = 0.5,
  col = c("black", "white"),
  normalize = NULL,
  zclip = NULL,
  overlay_alpha = 0.3,
  zlim = normalize,
  main = "",
  title_position = c("left", "top"),
  fun = NULL,
  nc = NA,
  which = NULL,
  ...
)

Arguments

volume

path to volume (underlay)
overlays

images to overlay on top of the underlay, can be either a vector of paths to the overlay volume images, or a sequence of named lists. Each list item has 'volume' (path to the volume) and 'color' (color of the overlay)
transform

rotation of the volume in scanner 'RAS' space
positions

vector of length 3 or matrix of 3 columns, the 'RAS' position of cross-hairs
zoom

zoom-in radio, default is 1
pixel_width

output image pixel resolution; default is 0.5, one pixel is 0.5 millimeters wide
col

color palette, can be a sequence of colors
normalize

range for volume data to be normalized; either NULL (no normalize) or a numeric vector of length two
zclip

clip image densities; if specified, values outside of this range will be clipped into this range
overlay_alpha

transparency of the overlay; default is 0.3
zlim

image plot value range, default is identical to normalize
main

image titles
title_position

title position; choices are "left" or "top"
fun

function with two arguments that will be executed after each image is drawn; can be used to draw cross-hairs or annotate each image
nc

number of "columns" in the plot when there are too many positions, must be positive integer; default is NA (automatically determined)
which

which plane to plot; default is NULL, which will trigger new plots and add titles; set to 1 for 'Axial' plane, 2 for 'Sagittal', and 3 for 'Coronal'.
...

additional arguments passing into image

Value

Nothing

Read 'FreeSurfer' ascii file

Description

Read 'FreeSurfer' ascii file

Usage

read_fs_asc(file)

Arguments

file

file location

Value

a list of vertices and face indices

Read FreeSurfer Annotations

Description

Read FreeSurfer Annotations

Usage

read_fs_labels(path, vertex_number)

Arguments

path

label path
vertex_number

force to reset vertex number if raw file is incorrect

Read 'FreeSurfer' m3z file

Description

Read 'FreeSurfer' m3z file

Usage

read_fs_m3z(filename)

Arguments

filename

file location, usually located at 'mri/transforms/talairach.m3z'

Details

An 'm3z' file is a 'gzip' binary file containing a dense vector field that describes a 3D registration between two volumes/images. This implementation follows the 'Matlab' implementation from the 'FreeSurfer'. This function is released under the 'FreeSurfer' license: https://surfer.nmr.mgh.harvard.edu/fswiki/FreeSurferSoftwareLicense.

Value

registration data

Read 'FreeSurfer' 'mgz/mgh' file

Description

Read 'FreeSurfer' 'mgz/mgh' file

Usage

read_fs_mgh_mgz(filename)

Arguments

filename

file location

Value

list contains coordinate transforms and volume data

Function to load surface data from 'Gifti' files

Description

The function 'read_gii2' is a dynamic wrapper of Python 'nibabel' loader. If no Python is detected, it will switch to 'gifti::readgii'.

Usage

read_gii2(path)

Arguments

path

'Gifti' file path

Format

An R function acting as safe wrapper for nibabel.load.

Function to load 'FreeSurfer' 'mgz/mgh' file

Description

The function 'read_mgz' is a dynamic wrapper of Python 'nibabel' loader. If no Python is detected, it will switch to built-in function 'read_fs_mgh_mgz', which has limited features.

Usage

read_mgz(path)

Arguments

path

'mgz/mgh' file path

Format

An R function acting as safe wrapper for nibabel.load.

Read volume file in 'MGH' or 'Nifti' formats

Description

Read volume file in 'MGH' or 'Nifti' formats

Usage

read_volume(file, format = c("auto", "mgh", "nii"), header_only = FALSE)

Arguments

file

file path
format

the file format
header_only

whether only read headers; default is false

Value

A list of volume data and transform matrices; if header_only=TRUE, then volume data will be substituted by the header.

Shiny Renderer for threeBrain Widgets

Description

Shiny Renderer for threeBrain Widgets

Arguments

expr

R expression that calls three_brain function or Brain object
env

environment of expression to be evaluated
quoted

is expr quoted? Default is false.

Author(s)

Zhengjia Wang

Function to reshape data to 'RAS' order

Description

Function to reshape data to 'RAS' order

Usage

reorient_volume(volume, Torig)

Arguments

volume

3-mode tensor (voxels), usually from 'mgz', 'nii', or 'BRIK' files
Torig

a 4x4 transform matrix mapping volume ('CRS') to 'RAS'

Value

Reshaped tensor with dimensions corresponding to 'R', 'A', and 'S'

Save threeBrain widgets to local file system

Description

Save threeBrain widgets to local file system

Usage

save_brain(widget, path, title = "3D Viewer", as_zip = FALSE, ...)

Arguments

widget

generated from function 'threejs_brain'
path

path to save the brain widget
title

widget title.
as_zip

whether to create zip file "compressed.zip".
...

ignored, used for backward compatibility

Author(s)

Zhengjia Wang

Create 'sEEG' shaft geometry prototype

Description

Intended for creating/editing geometry prototype, please see load_prototype to load existing prototype

Usage

seeg_prototype(
  type,
  center_position,
  contact_widths,
  diameter = 1,
  channel_order = seq_along(center_position),
  fix_contact = 1,
  overall_length = 200,
  description = NULL,
  dry_run = FALSE,
  default_interpolation = NULL,
  viewer_options = NULL,
  overwrite = FALSE
)

Arguments

type

type string and unique identifier of the prototype
center_position

numerical vector, contact center positions
contact_widths

numerical vector or length of one, width or widths of the contacts
diameter

probe diameter
channel_order

the channel order of the contacts; default is a sequence along the number
fix_contact

NULL or integer in channel_order, indicating which contact is the most important and should be fixed during the localization, default is 1 (inner-most target contact)
overall_length

probe length, default is 200
description

prototype description
dry_run

whether not to save the prototype configurations
default_interpolation

default interpolation string for electrode localization
viewer_options

list of viewer options; this should be a list of key-value pairs where the keys are the controller names and values are the corresponding values when users switch to localizing the electrode group
overwrite

whether to overwrite existing configuration file; default is false, which throws a warning when duplicated

Value

A electrode shaft geometry prototype; the configuration file is saved to 'RAVE' 3rd-party repository.

Examples

probe_head <- 2
n_contacts <- 12
width <- 2.41
contact_spacing <- 5
overall_length <- 400
diameter <- 1.12

contacts <- probe_head + width / 2 + 0:(n_contacts-1) * contact_spacing
proto <- seeg_prototype(
  type = "AdTech-sEEG-SD12R-SP05X-000",
  description = c(
    "AdTech sEEG - 12 contacts",
    "Contact length   : 2.41 mm",
    "Central spacing  : 5    mm",
    "Tip size         : 2    mm",
    "Diameter         : 1.12 mm"
  ),
  center_position = contacts,
  contact_widths = width,
  diameter = diameter,
  overall_length = overall_length,
  dry_run = TRUE
)

print(proto, details = FALSE)

R6 Class - Generate Sphere Geometry

Description

R6 Class - Generate Sphere Geometry

Author(s)

Zhengjia Wang

R6 Class - Generate Sphere Geometry

Description

R6 Class - Generate Sphere Geometry

Author(s)

Zhengjia Wang

Download and Manage Template Subjects

Description

Download and Manage Template Subjects

Usage

download_template_subject(
  subject_code = "N27",
  url,
  template_dir = default_template_directory()
)

download_N27(make_default = FALSE, ...)

set_default_template(
  subject_code,
  view = TRUE,
  template_dir = default_template_directory()
)

threebrain_finalize_installation(
  upgrade = c("ask", "always", "never", "data-only", "config-only"),
  async = TRUE
)

available_templates()

Arguments

subject_code

character with only letters and numbers (Important); default is 'N27'
url

zip file address; must be specified if subject_code is not from the followings: 'bert', 'cvs_avg35', 'cvs_avg35_inMNI152', 'fsaverage', 'fsaverage_sym', or 'N27'
template_dir

parent directory where subject's 'FreeSurfer' folder should be stored
make_default

logical, whether to make 'N27' default subject
...

more to pass to download_template_subject
view

whether to view the subject
upgrade

whether to check and download 'N27' brain interactively. Choices are 'ask', 'always', and 'never'
async

whether to run the job in parallel to others; default is true

Details

To view electrodes implanted in multiple subjects, it's highly recommended to view them in a template space The detail mapping method is discussed in function freesurfer_brain.

To map to a template space, one idea is to find someone whose brain is normal. In our case, the choice is subject 'N27', also known as 'Colin 27'. function download_N27 provides a simple and easy way to download a partial version from the Internet.

If you have any other ideas about template brain, you can use function set_default_template(subject_code, template_dir) to redirect to your choice. If your template brain is a 'Zip' file on the Internet, we provide function download_template_subject to automatically install it.

Author(s)

Zhengjia Wang

Create a brain object

Description

Create a brain object

Usage

threeBrain(
  path,
  subject_code,
  surface_types = "pial",
  atlas_types,
  ...,
  template_subject = unname(getOption("threeBrain.template_subject", "N27")),
  backward_compatible = getOption("threeBrain.compatible", FALSE)
)

Arguments

path

path to 'FreeSurfer' directory, or 'RAVE' subject directory containing 'FreeSurfer' files, or simply a 'RAVE' subject
subject_code

subject code, characters
surface_types

surface types to load; default is 'pial', other common types are 'white', 'smoothwm'
atlas_types

brain atlas to load; default is 'wmparc', or if not exists, 'aparc+aseg', other choices are 'aparc.a2009s+aseg', 'aparc.DKTatlas+aseg', depending on the atlas files in 'fs/mri' folder
...

reserved for future use
template_subject

template subject to refer to; used for group template mapping
backward_compatible

whether to support old format; default is false

Create a Threejs Brain and View it in Browsers

Description

Create a Threejs Brain and View it in Browsers

Usage

threejs_brain(
  ...,
  .list = list(),
  width = NULL,
  height = NULL,
  background = "#FFFFFF",
  cex = 1,
  timestamp = TRUE,
  title = "",
  side_canvas = FALSE,
  side_zoom = 1,
  side_width = 250,
  side_shift = c(0, 0),
  side_display = TRUE,
  control_panel = TRUE,
  control_presets = NULL,
  control_display = TRUE,
  camera_center = c(0, 0, 0),
  camera_pos = c(500, 0, 0),
  start_zoom = 1,
  symmetric = 0,
  default_colormap = "Value",
  palettes = NULL,
  value_ranges = NULL,
  value_alias = NULL,
  show_inactive_electrodes = TRUE,
  surface_colormap = system.file("palettes", "surface", "ContinuousSample.json", package
    = "threeBrain"),
  voxel_colormap = system.file("palettes", "datacube2", "FreeSurferColorLUT.json",
    package = "threeBrain"),
  videos = list(),
  widget_id = "threebrain_data",
  tmp_dirname = NULL,
  debug = FALSE,
  enable_cache = FALSE,
  token = NULL,
  controllers = list(),
  browser_external = TRUE,
  global_data = list(),
  global_files = list(),
  qrcode = NULL,
  custom_javascript = NULL,
  show_modal = "auto",
  embed = FALSE
)

Arguments

..., .list

geometries inherit from AbstractGeom
width, height

positive integers. Width and height of the widget. By default width='100%', and height varies.
background

character, background color such as "#FFFFFF" or "white"
cex

positive number, relative text magnification level
timestamp

logical, whether to show time-stamp at the beginning
title

viewer title
side_canvas

logical, enable side cameras to view objects from fixed perspective
side_zoom

numerical, if side camera is enabled, zoom-in level, from 1 to 5
side_width

positive integer, side panel size in pixels
side_shift

integer of length two, side panel shift in pixels ('CSS style': top, left)
side_display

logical, show/hide side panels at beginning
control_panel

logical, enable control panels for the widget
control_presets

characters, presets to be shown in control panels
control_display

logical, whether to expand/collapse control UI at the beginning
camera_center

numerical, length of three, XYZ position where camera should focus at
camera_pos

XYZ position of camera itself, default (0, 0, 500)
start_zoom

numerical, positive number indicating camera zoom level
symmetric

numerical, default 0, color center will be mapped to this value
default_colormap

character, which color map name to display at startup
palettes

named list, names corresponds to color-map names if you want to change color palettes
value_ranges

named list, similar to palettes, value range for each values
value_alias

named list, legend title for corresponding variable
show_inactive_electrodes

logical, whether to show electrodes with no values
surface_colormap

a color map or its path generated by create_colormap(gtype="surface") to render surfaces vertices; see create_colormap for details.
voxel_colormap

a color map or its path generated by create_colormap(gtype="volume") to render volume such as atlases; see create_colormap for details.
videos

named list, names corresponds to color-map names, and items are generated from video_content
widget_id

character, internally used as unique identifiers for widgets; only use it when you have multiple widgets in one website
tmp_dirname

character path, internally used, where to store temporary files
debug

logical, internally used for debugging
enable_cache

whether to enable cache, useful when rendering the viewers repeatedly in shiny applications
token

unique character, internally used to identify widgets in 'JavaScript' 'localStorage'
controllers

list to override the settings, for example proxy$get_controllers()
browser_external

logical, use system default browser (default) or built-in one.
global_data, global_files

internally use, mainly to store orientation matrices and files.
qrcode

'URL' to show in the 'QR' code; can be a character string or a named list of 'url' and 'text' (hyper-reference text)
custom_javascript

customized temporary 'JavaScript' code that runs after ready state; available 'JavaScript' variables are:

'groups'

input information about each group

'geoms'

input information about each geometry

'settings'

input information about canvas settings

'scene'

'threejs' scene object

'canvas'

canvas object

'gui'

controls data panel

'presets'

preset 'gui' methods
show_modal

logical or "auto", whether to show a modal instead of direct rendering the viewers; designed for users who do not have 'WebGL' support; only used in shiny applications
embed

whether to try embedding the viewer in current run-time; default is false (will launch default web browser); set to true if running in 'rmarkdown' or 'quarto', or to see the viewer in 'RStudio' default panel.

Author(s)

Zhengjia Wang

Examples

if( interactive() ) {
library(threeBrain)

# Please use `download_N27` to download N27 Collins template brain
n27_path <- file.path(default_template_directory(), "N27")
if( dir.exists(n27_path) ) {

  brain <- threeBrain(path = n27_path, subject_code = "N27",
                             surface_types = c('pial', 'smoothwm'))
  print(brain)

  brain$plot(
    background = "#000000",
    controllers = list(
      'Voxel Type' = 'aparc_aseg',
      'Surface Type' = 'smoothwm',
      'Blend Factor' = 1,
      'Right Opacity' = 0.3,
      'Overlay Sagittal' = TRUE
    ),
    show_modal = TRUE
  )

}
}

Shiny Output for threeBrain Widgets

Description

Shiny Output for threeBrain Widgets

Arguments

outputId

unique identifier for the widget
width, height

width and height of the widget. By default width="100 and height="500px".
reportSize

whether to report widget size in shiny session$clientData

Author(s)

Zhengjia Wang

R6 Class - Generate Tube Geometry

Description

R6 Class - Generate Tube Geometry

Author(s)

Zhengjia Wang

Add video content to the viewer

Description

Add video content to the viewer

Usage

video_content(
  path,
  duration = Inf,
  time_start = 0,
  asp_ratio = 16/9,
  local = TRUE
)

Arguments

path

local file path or 'URL'
duration

duration of the video
time_start

start time relative to the stimuli onset
asp_ratio

aspect ratio; default is 16/9
local

used only when path is a 'URL': whether to download the video before generating the viewer; see 'Details'

Details

The video path can be either local file path or a 'URL' from websites. When path is from the internet, there are two options: download the video before generating the viewer, or directly use the 'URL'.

If download happens before a viewer is generated (local=TRUE), then the video content is local. The viewer will be self-contained. However, the distribution will contain the video, and the archive size might be large.

If raw 'URL' is used (local=FALSE), then viewer is not self-contained as the video link might break anytime. The 'screenshot' and 'record' function might be limited if the 'URL' has different domain than yours. However, the distribution will not contain the video, hence smaller. This works in the scenarios when it is preferred not to share video files or they are licensed, or simply distribution is limited. Besides, this method is slightly faster than the local alternatives.

Generate surface file from 'nii' or 'mgz' volume files

Description

Generate surface file from 'nii' or 'mgz' volume files

Usage

volume_to_surf(
  volume,
  save_to = NA,
  lambda = 0.2,
  degree = 2,
  threshold_lb = 0.5,
  threshold_ub = NA,
  format = "auto"
)

Arguments

volume

path to the volume file, or object from read_volume.
save_to

where to save the surface file; default is NA (no save).
lambda

'Laplacian' smooth, the higher the smoother
degree

'Laplacian' degree; default is 2
threshold_lb

lower threshold of the volume (to create mask); default is 0.5
threshold_ub

upper threshold of the volume; default is NA (no upper bound)
format

The format of the file if save_to is a valid path, choices include

'auto'

Default, supports 'FreeSurfer' binary format and 'ASCII' text format, based on file name suffix

'bin'

'FreeSurfer' binary format

'asc'

'ASCII' text format

'ply'

'Stanford' 'PLY' format

'off'

Object file format

'obj'

'Wavefront' object format

'gii'

'GIfTI' format. Please avoid using 'gii.gz' as the file suffix

'mz3'

'Surf-Ice' format

'byu'

'BYU' mesh format

'vtk'

Legacy 'VTK' format

'gii', otherwise 'FreeSurfer' format. Please do not use 'gii.gz' suffix.

Value

Triangle 'rgl' mesh (vertex positions in native 'RAS'). If save_to is a valid path, then the mesh will be saved to this location.

See Also

read_volume, vcg_isosurface, vcg_smooth_implicit

Examples

library(threeBrain)
N27_path <- file.path(default_template_directory(), "N27")
if(dir.exists(N27_path)) {
  aseg <- file.path(N27_path, "mri", "aparc+aseg.mgz")

  # generate surface for left-hemisphere insula
  mesh <- volume_to_surf(aseg, threshold_lb = 1034,
                         threshold_ub = 1036)

  if(interactive()) {
    ravetools::rgl_view({
      ravetools::rgl_call("shade3d", mesh, color = "yellow")
    })
  }
}

Color maps for volume or surface data

Description

Color maps for volume or surface data

Usage

create_colormap(
  gtype = c("surface", "volume"),
  dtype = c("continuous", "discrete"),
  key,
  color,
  value,
  alpha = FALSE,
  con = NULL,
  auto_rescale = FALSE,
  ...
)

save_colormap(cmap, con)

freeserfer_colormap(con)

load_colormap(con)

Arguments

gtype

geometry type, choices are "surface", "volume"
dtype

data type, "continuous" or "discrete"
key

non-negative integer vector corresponding to color values; its length must exceed 1; see 'Details'
color

characters, corresponding to color strings for each key
value

actual value for each key
alpha

whether to respect transparency
con

a file path to write results to or to read from. The file path can be passed as voxel_colormap into threejs_brain.
auto_rescale

automatically scale the color according to image values; only valid for continuous color maps
...

used by continuous color maps, passed to colorRampPalette
cmap

color map object

Details

Internal 'JavaScript' shader implementation uses integer color keys to connect color palettes and corresponding values. The keys must be non-negative.

Zero key is a special color key reserved by system. Please avoid using it for valid values.

Value

A list of color map information

Examples

# Creates a symmetric continuous colormap with 3 keys
# The color range is -10 to 10
# The colors are 'blue','white','red' for these keys

pal <- create_colormap(
  gtype = "volume", dtype = "continuous",
  key = c(1,2,3), value = c(-10,0,10),
  color = c('blue','white','red'))

print( pal )

# ---------------- Get colormap key from a value ------------

# returns key index starting from
pal$get_key( -10 )

# nearest value
pal$get_key( 2 )

# set threshold, key is now 0 (no color)
pal$get_key( 2, max_delta = 1 )


# ---------------- Save and load ----------------
f <- tempfile( fileext = '.json' )
save_colormap( pal, f )
cat(readLines(f), sep = '\n')

load_colormap(f)

Generate volume data from 'MNI' coordinates

Description

Generate volume data from 'MNI' coordinates

Usage

add_voxel_cube(
  brain,
  name,
  cube,
  size = c(256, 256, 256),
  trans_mat = NULL,
  trans_space_from = c("model", "scannerRAS"),
  color_format = c("RGBAFormat", "RedFormat")
)

add_nifti(
  brain,
  name,
  path,
  trans_mat = NULL,
  color_format = c("RGBAFormat", "RedFormat"),
  trans_space_from = c("model", "scannerRAS")
)

create_voxel_cube(
  mni_ras,
  value,
  colormap,
  keys = colormap$get_key(value),
  dimension = c(256, 256, 256)
)

Arguments

brain

a 'threeBrain' brain object generated from freesurfer_brain2 or merge_brain. If you have 'rave' package installed, the brain can be generated from rave::rave_brain2
name

the name of voxel cube, only letters, digits and '_' are allowed; other characters will be replaced by '_'
cube

a 3-mode array; see the following example
size

the actual size of the volume, usually dot multiplication of the dimension and voxel size
trans_mat

the transform matrix of the volume. For add_voxel_cube, this matrix should be from data cube geometry model center to world ('tkrRAS') transform. For add_nifti, this matrix is the 'Nifti' 'RAS' to world ('tkrRAS') transform.
trans_space_from

where does trans_mat transform begin; default is from object 'model' space; alternative space is 'scannerRAS', meaning the matrix only transform volume cube from its own 'scannerRAS' to the world space.
color_format

color format for the internal texture. Default is 4-channel 'RGBAFormat'; alternative choice is 'RedFormat', which saves volume data with single red-channel to save space
path

'Nifti' data path
mni_ras

'MNI' 'RAS' coordinates, should be a n-by-3 matrix
value

data values (length n); used if keys is missing
colormap

a color map generated from create_colormap; see voxel_colormap for details
keys

integer color-keys generated from a color map with length of n; alternatively, you could specify value and colormap to generate keys automatically
dimension

volume dimension; default is a 256 x 256 x 256 array cube; must be integers and have length of 3

Value

create_voxel_cube returns a list of cube data and other informations; add_voxel_cube returns the brain object

Examples

# requires N27 brain to be installed
# use `download_N27()` to download template Collins brain


# sample MNI coords
tbl <- read.csv(system.file(
  'sample_data/example_cube.csv', package = 'threeBrain'
))
head(tbl)

# load colormap
cmap <- load_colormap(system.file(
  'palettes/datacube2/Mixed.json', package = 'threeBrain'
))

x <- create_voxel_cube(
  mni_ras = tbl[, c('x', 'y', 'z')],
  keys = tbl$key,
  dimension = c(128, 128, 128)
)


n27_path <- file.path(default_template_directory(), "N27")
if( interactive() && dir.exists(n27_path) ) {
  brain <- merge_brain()

  # or add_voxel_cube(brain, 'example', x$cube)
  x$add_to_brain(brain, 'example')

  brain$plot(controllers = list(
    "Voxel Type" = 'example',
    'Right Opacity' = 0.3,
    'Left Opacity' = 0.3,
    'Background Color' = '#000000'
  ), voxel_colormap = cmap)
}