Traverse groups function seems to be stuck on the first object without increasing the array or returning anything. Eventually it hits the recursion limit and errors

Questions
1 
function traverseGroups(group) {
	let allObjects = [];
	group.traverse(function(object) {
		console.log(allObjects);
		console.log(object);
		if(object.type === 'Group') {
			allObjects.push(...traverseGroups(object));
		} else {
			allObjects.push(object);
		};
	});
	return(allObjects);
};

I tried to create an array, then traverse through the group, appending the traverseGroup of the childObject to the array if the childObject is a group, otherwise simply the appending the childObject to the array.

This doesn’t seem to be working, as with the console.log statements I can see that the array seems to remain empty and the object seems to be the same every time (Object { isObject3D: true, uuid: "bd88a831-bd88-4d88-acfc-dff9118f960f", name: "Scene", type: "Group", parent: {…}, children: (13) […], up: {…}, position: {…}, rotation: {…}, quaternion: {…}, … }).

I already asked Bing about this, and I followed a couple of it’s suggestions, such as using === rather than ==, and .push() rather than .concat()

Can you please help?

2

Your observation that the same object is printed in the console is correct.

Here is a small hint:

According to the documentation of Object3D.traverse, it executes the callback on the provided object and all descendants. So, if you call traverseGroups with a group, the first value of parameter object will be the same group … and this will push the execution into infinite loop … until the stack gives up.

I hope you can see how to fix your code (i.e. I do not want to steal from you the joy of fixing your own code). However, let me know if you need more help.

3

Is there a function that only does it on the descendents, not the current object?

4

Here is one solution using your style. Does it do what you want?

function traverseGroups(group) {
	let allObjects = [];
	group.traverse( function(object) {
		if( object.type !== 'Group' )
			allObjects.push(object);
	} );
	return allObjects;
}
2 Likes
5

You can loop through all immediate descendents of object with a loop:

for (let child of object.children) {
   // do whatever you want with child
}
2 Likes
6

No, because I want it to go inside groups and return all the individual elements inside them.

7

Have you tried it?

1 Like
8

I don’t get why you’re not just using…

function traverseGroups(group) {
	let allObjects = [];
	group.traverse(function(object) {
             allObjects.push(object);
	});
	return(allObjects);
};

Won’t this just push all descendants, group or not, to the allObjects array?

9

Yeah I tried that it’s working now, thanks!

10

Not in arrays in arrays?