Remove materials, textures and images from GLTF files

gltfstrip.nim

import docopt
import json

let doc = """
gltfstrip

Remove materials, textures and images from GLTF files

Usage:
    gltfstrip [-b] <file>...
    gltfstrip (-h | --help)

Options:
  -h --help     Show this screen.
  -b --buffers  Also remove meshes, accessors and buffers
"""

let args = docopt(doc)


var files = @(args["<file>"])

proc gltfstrip(input: string): string

for f in files:
  let str = readFile(f)
  let res = gltfstrip(str)
  writeFile(f, res)
  echo "stripped " & f

proc gltfstrip(input:string): string =
  var json = parseJson(input)

  template safeDelete(j, k) =
    if j.hasKey(k):
      j.delete(k)

  if json.hasKey("meshes"):
    for mesh in json["meshes"]:
      for primitive in mesh["primitives"]:
        primitive.safeDelete("material")

  json.safeDelete("textures")
  json.safeDelete("images")

  if args["--buffers"]:
    if json.hasKey("nodes"):
      for node in json["nodes"]:
        node.safeDelete("mesh")
    json.safeDelete("meshes")
    json.safeDelete("accessors")
    json.safeDelete("bufferViews")
    json.safeDelete("buffers")

  pretty(json)

1. Install Nim: https://nim-lang.org/
2. Install docopt dependency: nimble install docopt
3. Compile: nim c gltfstrip.nim
4. Run ./gltfstrip file1 file2 file3