useLargeWorldRendering / Instance mesh / loss of precision

Bugs
1

Hello everyone,

I have few problem while using useLargeWorldRendering combined with Instance Meshes.

My app is a World/Earth representation (Ellipsoid) where the unit is the meter. I’m experiencing a noticeable positioning drift when switching to instances.

Here are two screenshots to illustrate the issue:

The first one uses individual Mesh/Box : the positioning is perfect.

The second one uses Instances: you can see a significant loss of precision in the placement.

Is this expected behavior when using useLargeWorldRendering with instances? I’m a bit lost on how to get high precision for instanced objects at world scale.

[EDIT] : Here is a playground where I can reproduce the problem
https://playground.babylonjs.com/#XXXLBM ->you have to zoom out to see the boxes.
uncomment/comment line 38/45 to switch from boxes to instances.

Just reporting this as a heads-up. I’m in early dev and I know you’re all busy with the v9 release. Just wanted to share my findings.

Meshes :

mesh
mesh1920×1021 267 KB

Instances :

instance
instance1920×1021 251 KB

2 Likes
2

cc @georgie

3

ThinInstance seems to be a solution. but a bit more complex to manage than myMesh.createInstance('')

https://playground.babylonjs.com/#7CVJG9 you have to zoom out to see boxes.

4

@samuelgirardin thanks for reporting, I will take a look!

5

@georgie , thanks for the fix !

1 Like
6

@samuelgirardin You’re welcome! I’m glad you noticed it was fixed, I was busy in release land and forgot to update the forum after checkin, sorry about that! thanks for reporting and please continue to share any issues you run into!

1 Like