readglTF {rgl2gltf}

Read a glTF file

Description

The glTF file is the JSON part of a glTF representation of a 3D scene. This function reads one and returns a "gltf" object containing the information in R format.

Typically most of the data for the scene is contained in other files named in this one, usually found in the same file folder.

Usage

readglTF(path, defaultbin = NULL, ...)

Arguments

path

The path to the file being read. R connections cannot be used.

defaultbin

The name of the default associated binary file, if it is not named in the JSON. This is typically used when the JSON has been extracted from a GLB file.

...

Not currently used.

Value

An object of class "gltf".

Author(s)

Duncan Murdoch

References

The specification of the glTF format: https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html

Examples

# This web page has lots of sample files

samples <- "https://raw.githubusercontent.com/KhronosGroup/glTF-Sample-Models/master/2.0"
filename <- tempfile(fileext = ".gltf")

# Get one of them:  a 2 cylinder engine.  We need both parts
# to be able to view it, though only the .gltf part is
# needed for readglTF()

download.file(paste0(samples, "/2CylinderEngine/glTF/2CylinderEngine.gltf"),
  destfile = filename)
download.file(paste0(samples, "/2CylinderEngine/glTF/2CylinderEngine0.bin?raw=true"),
  destfile = file.path(tempdir(), "2CylinderEngine0.bin"),
  mode = "wb")

gltf <- readglTF(filename)
gltf

# gltf files contain references to other files using
# relative paths, so we can only use them from their
# own directory
olddir <- setwd(dirname(filename))
rgl::plot3d(gltf)
setwd(olddir)