DRAFT for handling gltfUpAxis in upgrade

src/tools/contentProcessing/GltfUtilities.ts

@@ -8,6 +8,9 @@ import { Extensions } from "../../tilesets";
 import { GltfPipelineLegacy } from "./GltfPipelineLegacy";
 import { GltfWeb3dQuantizedAttributes } from "./GltfWeb3dQuantizedAttributes";
 
+import { Loggers } from "../../base";
+const logger = Loggers.get("contentProcessing");
+
 /**
  * Internal utility methods related to glTF/GLB data.
  *
@@ -293,11 +296,13 @@ export class GltfUtilities {
     if (!rtcExtension) {
       return;
     }
-    // Compute the translation, taking the y-up-vs-z-up transform into account
+
+    // Compute the translation
+    logger.info("Applying RTC for gltfUpAxis=Z");
     const rtcTranslation = [
       rtcExtension.center[0],
+      rtcExtension.center[1],
       rtcExtension.center[2],
-      -rtcExtension.center[1],
     ];
     const scenes = gltf.scenes;
     if (!scenes) {

src/tools/migration/TileFormatsMigration.ts

@@ -1,4 +1,4 @@
-import { Document } from "@gltf-transform/core";
+import { Document, mat4 } from "@gltf-transform/core";
 
 import { TileFormatsMigrationPnts } from "./TileFormatsMigrationPnts";
 import { TileFormatsMigrationB3dm } from "./TileFormatsMigrationB3dm";
@@ -78,6 +78,31 @@ export class TileFormatsMigration {
     );
   }
 
+  /**
+   * Apply the given transform to a new root in the given glTF-Transform
+   * document.
+   *
+   * The given transform is assumed to be a 16-element array that
+   * describes the 4x4 transform matrix, in column major order.
+   *
+   * @param document - The glTF-Transform document
+   * @param transform - The transform
+   */
+  static applyTransform(document: Document, transform: number[]) {
+    const root = document.getRoot();
+    const scenes = root.listScenes();
+    for (const scene of scenes) {
+      const oldChildren = scene.listChildren();
+      for (const oldChild of oldChildren) {
+        const newRoot = document.createNode();
+        newRoot.setMatrix(transform as mat4);
+        scene.removeChild(oldChild);
+        newRoot.addChild(oldChild);
+        scene.addChild(newRoot);
+      }
+    }
+  }
+
   /**
    * Apply the given RTC_CENTER to the given glTF-Transform document,
    * by inserting a new root node that carries the given RTC_CENTER

src/tools/migration/TileFormatsMigrationB3dm.ts

@@ -56,13 +56,18 @@ export class TileFormatsMigrationB3dm {
     // a new root node above each scene node, that carries the
     // RTC_CENTER as its translation
     if (featureTable.RTC_CENTER) {
+      logger.info("Applying RTC center");
       const rtcCenter = TileTableData.obtainRtcCenter(
         featureTable.RTC_CENTER,
         featureTableBinary
       );
       TileFormatsMigration.applyRtcCenter(document, rtcCenter);
     }
 
+    logger.info("Applying axis conversions");
+    const axisConversion = [1, 0, 0, 0, 0, 0, -1, 0, 0, 1, 0, 0, 0, 0, 0, 1];
+    TileFormatsMigration.applyTransform(document, axisConversion);
+
     // If there are batches, then convert the batch table into
     // an `EXT_structural_metadata` property table, and convert
     // the `_BATCHID` attributes of the primitives into

src/tools/tilesetProcessing/upgrade/TilesetObjectUpgrader.ts

@@ -61,6 +61,12 @@ export class TilesetObjectUpgrader {
       logger.debug(`Upgrading extension declarations`);
       Extensions.removeExtensionUsed(tileset, "3DTILES_content_gltf");
     }
+
+    const asset = tileset.asset as any;
+    if (asset.gltfUpAxis !== undefined) {
+      logger.info(`Removing glTFUpAxis declaration`);
+      delete asset.gltfUpAxis;
+    }
   }
 
   /**