model scale - scene scale - in AR


I have created a scene in real scale - with lots of spawn objects that are animated in world position in timelines for each actor.

Now im putting it in AR with Arkit - and wish to put it on a table = scale it down to 0.1 or so.

How can i do this? - i imagine that if there is a general scene scale - then the camera movement will also be scaled - and not fit the actual 3d tracking from ARkit

But i tried scaling all down - by attaching all objects and actors to another object that was then scaled - but all the animation of cause still happen in real world scale.

So any ideas anyone ? :slight_smile:

Best regards

Yeah, you either need to create all content with your scale in mind, or implement some technical changes. I got support saying this:

"The current ARKit integration relies on the World to Meters being fixed at 100.0f, which is the UE4 default value. Improving this is slated for the next release.

In the mean time, you would need to add your own scaling transform. You would want to look at AppleARKitSystem.cpp and/or UCameraComponent::GetCameraView, which is where we apply the tracking transform to the camera. Additionally, you’ll want to transform any hit-test results accordingly. Note that hit-test result are being returned in the Camera’s Parent’s space; i.e. the Tracking Space."

And this is still different from ARCore scaling. Hopefully they will soon implement correct settings into the World to Meters.

Hi StephaBon - thanks a lot for your reply.

Now after 4.18 is released have you seen any other/easier options?

I assume not - but would be really great if they did…

StephaBon - do you have more detail on this technique? I have a similar problem and would like to make a full scale model (of a home) table top size, without having to resize it.

Would love more info on this too.