From 3fe48b4fd928c271bb3231ddc36392a5f8bf0067 Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Sat, 29 Jan 2022 11:35:26 -0500
Subject: [PATCH] add 3mf instancing support

---
 src/load/3mf.js | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/load/3mf.js b/src/load/3mf.js
index c6cfb373..02477cd2 100644
--- a/src/load/3mf.js
+++ b/src/load/3mf.js
@@ -7,6 +7,7 @@
 let load = self.load = self.load || {};
 if (load.TMF) return;
 
+// dep: add.three
 // dep: ext.jszip
 gapp.register('load.3mf');
 
@@ -14,6 +15,8 @@ load.TMF = {
     parseAsync
 };
 
+let { BufferAttribute, Matrix4 } = THREE;
+
 function query(node, path, fn) {
     let collect = false;
     let match = path[0];
@@ -41,7 +44,6 @@ function loadModel(doc) {
         let id;
         let model;
         let faces;
-        let refs;
         let units;
         let scale = 1;
         let scaleMap = {
@@ -75,14 +77,22 @@ function loadModel(doc) {
                     // emit previous model
                     emitModel();
                     faces = [];
-                    refs = [];
                     id = node.getAttribute("id") || undefined;
                     model = node.getAttribute("name") || undefined;
                     query(node, ["components","+component"], (type, node) => {
                         let objectid = node.getAttribute('objectid');
-                        let trans = node.getAttribute('transform');
-                        refs.push({ objectid, trans });
-                        // console.log({objectid, trans });
+                        let mat = node.getAttribute('transform').split(' ').map(v => parseFloat(v));
+                        mat = [
+                            ...mat.slice(0,3), 0,
+                            ...mat.slice(3,6), 0,
+                            ...mat.slice(6,9), 0,
+                            ...mat.slice(9,12), 1
+                        ];
+                        let ref = byid[objectid];
+                        if (!ref) return;
+                        let m4 = new Matrix4().fromArray(mat);
+                        let pos = new BufferAttribute(ref.faces.toFloat32(), 3).applyMatrix4(m4);
+                        faces.appendAll(pos.array);
                     });
                     break;
                 case "mesh":