Controlling Model Size in AR Environment

[abhirami100]

I'm encountering an issue with controlling the size of models. Specifically, I'm trying to display a chair in the AR view at a standard size, but no matter what adjustments I make to the model's size, it always appears smaller than I'd like in the AR environment.

I've tried scaling the model up, but when I view it in the AR viewer, it seems to default to its original size. Is there a way to set a fixed size for a model in AR so that it consistently appears at the desired scale?

[danilokrulj]

You set the correct scale while editing the model (in blender or some other 3D program). And you add ar-scale="fixed" to the element, that will keep your model at 100% scale.

PS.
It might seem smaller/larger if tracking doesn't get the ground plane right, but if you scan enough it should correct it.

[abhirami100]

When I verify that the dimensions match those in Blender, and they do, do I need to adjust any settings so that if I scan a closer area, the model will appear larger ?
For example: https://ar.herabathroom.com/bathtub.html

[elalish]

Can you paste in some screen recordings so we can tell what problem you're seeing? I bet you're just not finding the floor (notoriously finicky with AR).

[abhirami100]

chair.mp4

Here is the code,
<model-viewer
src="https://cdn.glitch.global/298a568e-26d1-4b26-80ab-19ad8a8d013b/sofa_chair.glb?v=1710419019526"
ar
ar-scale="fixed"
camera-controls
touch-action="pan-y"
alt="A 3D model of an chair"
shadow-intensity="2"

[elalish]

Yes, it's exactly as I thought - ARCore hasn't found your room's floor yet, because it requires parallax to do so. You have to move your phone side-to-side (not just turn it) for this to work, and you'll know it happens when the model jumps up / down to the floor height and the shadow shows up.

Take a look at how the AR prompt is designed in my above link - you may want to copy that or make something similar to help your users.

[abhirami100]

Even with proper scanning and positioning attempts, the issue persists with this code. However, when I use "ar-modes='scene-viewer" ,the model displays in the correct size.