add python code to convert geojson to json

.gitignore

@@ -23,3 +23,6 @@ Testing/
 doc/doxygen/
 *.xcf
 tests/unit_tests/approval_tests/received/*
+contrib/gplate/data
+contrib/gplate/plate-model-repo
+contrib/pmm.log

contrib/gplate/geojson2json.ipynb

@@ -0,0 +1,108 @@
+{
+ "cells": [
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Geojson2json.py is a simple script that directly converts GeoJSON files extracted using the GPlates GUI to the World Builder-compatible JSON format. Currently, it supports continental plate geometries. \n",
+    "\n",
+    "The script reads the GeoJSON file, processes polygon features, and assigns default or provided values for \n",
+    "maximum depth and compositions. The output JSON file follows the World Builder structure, making it ready \n",
+    "for use in geodynamic modeling applications.\n",
+    "\n",
+    "Future improvements may integrate this script with GPlate2GWB for a more streamlined workflow.\n",
+    "\n",
+    "Usage:\n",
+    "    python geojson2json.py\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import json\n",
+    "\n",
+    "# Configuration defined by the user\n",
+    "geojson_file = \"reconstructed_400.00Ma.geojson\"  # Input GeoJSON file\n",
+    "output_file = \"world_builder_model.json\"         # Output JSON file\n",
+    "default_max_depth = 350e3\n",
+    "default_compositions = [0]\n",
+    "\n",
+    "try:\n",
+    "    # Load GeoJSON file\n",
+    "    with open(geojson_file, 'r') as f:\n",
+    "        geojson_data = json.load(f)\n",
+    "\n",
+    "    features = []\n",
+    "\n",
+    "    for feature in geojson_data.get('features', []):\n",
+    "        if feature.get('geometry', {}).get('type') == 'Polygon':\n",
+    "            name = feature.get('properties', {}).get('NAME', 'Unknown')\n",
+    "            coordinates = [list(coord) for coord in feature['geometry']['coordinates'][0]]\n",
+    "\n",
+    "            # Use provided properties or fall back to defaults\n",
+    "            max_depth = feature.get('properties', {}).get('MAX_DEPTH', default_max_depth)\n",
+    "            compositions = feature.get('properties', {}).get('COMPOSITIONS', default_compositions)\n",
+    "\n",
+    "            feature_data = {\n",
+    "                \"model\": \"continental plate\",\n",
+    "                \"name\": name,\n",
+    "                \"max depth\": max_depth,\n",
+    "                \"coordinates\": coordinates,\n",
+    "                \"composition models\": [\n",
+    "                    {\n",
+    "                        \"model\": \"uniform\",\n",
+    "                        \"compositions\": compositions,\n",
+    "                        \"max depth\": max_depth\n",
+    "                    }\n",
+    "                ]\n",
+    "            }\n",
+    "            features.append(feature_data)\n",
+    "\n",
+    "    output_data = {\n",
+    "        \"version\": \"1.1\",\n",
+    "        \"interpolation\": \"continuous monotone spline\",\n",
+    "        \"coordinate system\": {\n",
+    "            \"model\": \"spherical\",\n",
+    "            \"depth method\": \"starting point\"\n",
+    "        },\n",
+    "        \"features\": features\n",
+    "    }\n",
+    "\n",
+    "    # Save output to JSON file\n",
+    "    with open(output_file, 'w') as out_f:\n",
+    "        json.dump(output_data, out_f, indent=4)\n",
+    "\n",
+    "    print(f\"Conversion successful! Output saved to {output_file}\")\n",
+    "\n",
+    "except Exception as e:\n",
+    "    print(f\"Error processing file: {e}\")\n"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "extra_postprocess",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.15"
+  },
+  "orig_nbformat": 4
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

tests/gwb-grid/continental_plate_composition_random.wb

@@ -15,3 +15,4 @@
     }
   ]
 }
+