fix normal vectors being zero

src/extensions/geo-export/glb-exporter.ts

@@ -17,9 +17,7 @@ import { MeshExporter } from './mesh-exporter';
 const v3fromArray = Vec3.fromArray;
 const v3transformMat4 = Vec3.transformMat4;
 const v3transformMat3 = Vec3.transformMat3;
-const v3isZero = Vec3.isZero;
 const v3normalize = Vec3.normalize;
-const v3set = Vec3.set;
 const v3toArray = Vec3.toArray;
 const mat3directionTransform = Mat3.directionTransform;
 
@@ -84,11 +82,7 @@ export class GlbExporter extends MeshExporter<GlbData> {
         for (let i = 0; i < vertexCount; ++i) {
             if (i % 1000 === 0 && ctx.shouldUpdate) await ctx.update({ current: currentProgress + vertexCount + i });
             v3fromArray(tmpV, normals, i * stride);
-            if (v3isZero(tmpV)) { // FIXME: Happens with 1MBN
-                v3set(tmpV, 0, 0, 1);
-            } else {
-                v3transformMat3(tmpV, v3normalize(tmpV, tmpV), n);
-            }
+            v3transformMat3(tmpV, v3normalize(tmpV, tmpV), n);
             v3toArray(tmpV, normalArray, i * 3);
         }
 

src/extensions/geo-export/mesh-exporter.ts

@@ -116,7 +116,7 @@ export abstract class MeshExporter<D extends RenderObjectExportData> implements
             const normals = mesh.normalBuffer.ref.value;
             const indices = mesh.indexBuffer.ref.value;
             const groups = mesh.groupBuffer.ref.value;
-            await this.addMeshWithColors(vertices, normals, indices, groups, vertices.length / 3, indices.length, values, instanceIndex, false, ctx);
+            await this.addMeshWithColors(vertices, normals, indices, groups, mesh.vertexCount, indices.length, values, instanceIndex, false, ctx);
         }
     }
 
@@ -154,7 +154,7 @@ export abstract class MeshExporter<D extends RenderObjectExportData> implements
             const normals = mesh.normalBuffer.ref.value;
             const indices = mesh.indexBuffer.ref.value;
             const groups = mesh.groupBuffer.ref.value;
-            await this.addMeshWithColors(vertices, normals, indices, groups, vertices.length / 3, indices.length, values, instanceIndex, false, ctx);
+            await this.addMeshWithColors(vertices, normals, indices, groups, mesh.vertexCount, indices.length, values, instanceIndex, false, ctx);
         }
     }