Fix transformations not applied

package.json

@@ -63,6 +63,7 @@
   },
   "dependencies": {
     "lodash": "^4.17.5",
-    "matrixmath": "^2.2.2"
+    "matrixmath": "^2.2.2",
+    "three": "^0.103.0"
   }
 }

src/gltf1-bounding-box.js

@@ -3,6 +3,7 @@ import { flattenDeep, includes } from 'lodash';
 import { loadPositions } from './gltf-reader';
 
 import precise from './precise';
+import trsMatrix from './trs-matrix';
 
 const gltf1BoundingBox = {
 
@@ -70,8 +71,8 @@ const gltf1BoundingBox = {
         includes(nodes[nodeName].children, childNodeName)
       );
 
-    // Specify identity matrix if not present
-    const nodeMatrix = nodes[childNodeName].matrix || [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
+    // Get matrix or compose TRS fields if present, TRS is by default Identity
+    const nodeMatrix = nodes[childNodeName].matrix || trsMatrix.getTRSMatrix(nodes[childNodeName]);;
 
     return parentNodeName ?
 

src/gltf2-bounding-box.js

@@ -3,6 +3,7 @@ import { flattenDeep, includes } from 'lodash';
 import { loadPositions } from './gltf-reader';
 
 import precise from './precise';
+import trsMatrix from './trs-matrix';
 
 const gltf2BoundingBox = {
 
@@ -61,8 +62,8 @@ const gltf2BoundingBox = {
         includes(node.children, childNode.index)
       );
 
-    // Specify identity matrix if not present
-    const childNodeMatrix = childNode.matrix || [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
+    // Get matrix or compose TRS fields if present, TRS is by default Identity
+    const childNodeMatrix = childNode.matrix || trsMatrix.getTRSMatrix(childNode);
 
     return (parentNode !== undefined) ?
 

src/trs-matrix.js

@@ -0,0 +1,67 @@
+import { Matrix4, Quaternion } from 'three';
+
+const trsMatrix = {
+
+    /**
+     * Get the composed TRS (trasnlation, rotation, scale) affine transformation matrix for a given node.
+     *
+     * @param {Object} node a node in a GLTF
+     * @param {Array<number>} [node.translation] array of 3 values for a translation
+     * @param {Array<number>} [node.rotation] an array of four values for a rotation (quaternion)
+     * @param {Array<number>} [node.scale] an array of three values for a scale
+     */
+    getTRSMatrix({ translation, rotation, scale }) {
+        const t = translation ? trsMatrix._affineT(translation) : trsMatrix._I();
+        const r = rotation ? trsMatrix._affineR(rotation) : trsMatrix._I();
+        const s = scale ? trsMatrix._affineS(scale) : trsMatrix._I();
+
+        // Post-multiply: T * R * S
+        const TRS = t.multiply(r).multiply(s);
+
+        // toArray returns a column-major, and we need exactly that one
+        return TRS.toArray();
+    },
+
+    /**
+     * Three functions that use `_affine`, to simplify calls above.
+     */
+    _affineT(t) {
+        return trsMatrix._affine({ t });
+    },
+    _affineR(r) {
+        return trsMatrix._affine({ r });
+    },
+    _affineS(s) {
+        return trsMatrix._affine({ s });
+    },
+
+    /**
+     * Identity 4x4 matrix.
+     */
+    _I() {
+        return new Matrix4().identity();
+    },
+
+    /**
+     * Convert one of the t, r, or s arrays into a 4x4 affine transformation matrix.
+     * The passed parameter object p should contain only one of the fields t, r, or s.
+     *
+     * @param {Object} p
+     * @param {Array<number>} [p.t] an array of three values for a transaltion
+     * @param {Array<number>} [p.r] an array of four values for a rotation (quaternion)
+     * @param {Array<number>} [p.s] an array of three values for a scale
+     */
+    _affine({ t, r, s }) {
+        if (t) {
+            return new Matrix4().makeTranslation(t[0], t[1], t[2]);
+        }
+        if (r) {
+            return new Matrix4().makeRotationFromQuaternion(new Quaternion(r[0], r[1], r[2], r[3]));
+        }
+        if (s) {
+            return new Matrix4().makeScale(s[0], s[1], s[2]);
+        }
+    },
+};
+
+export default trsMatrix;