From babylonjs v 8.13.1 the compressed PLY GS with SH looks wrong

Bugs
1

Hi,

We were updating our Babylon version to the latest one and we have seen that from 8.13.1 on, the PLY GS files with Spherical harmonics are displayed wrong.

The same compressed PLY looks good in 8.9.1 (scaled -1 in Y):

image
image673×816 147 KB

And looks wrong from 8.13.1 to the latest current version (8.40.1) -scaled -1 in X:

image
image638×907 174 KB

In both cases the scene was configured with useRightHandedSystem=true as we are combining with GLB files in some cases.

I’m not sure if it may be produced by this GS SH View Direction by CedricGuillemet · Pull Request #16804 · BabylonJS/Babylon.js · GitHub, as it’s the only thing related to GS in that 8.13.1 version. I have tried in the Babylon sandbox and the issue is the same.

I’m also having this wrong appearance with SPZ files with SH.

The dragon model is from this post: Gaussian Splatting seems to not work since version 8 - #32 by SonnyC56 and reexported in Supersplat to a compressed PLY

Regards

3

I’m taking a look!

4

Issue will be fixed by Remove viewDirectionFactor for GS SH by CedricGuillemet · Pull Request #17544 · BabylonJS/Babylon.js · GitHub

2 Likes
6

Does that also apply to the SOG, or only the PLY and SPZ implementation?

Best. Werner

7

the removed uniform was in shaders, so it impact all renderings. PR unifies file loading accross all formats.

1 Like
8

@Cedric Do you have an estimate of when the fix might be integrated into production?

Thanks

9

I don’t like giving ETA :slight_smile: Hopefully, next monday or tuesday. I have a sync issue to properly fix and this it typically the kind of problem that takes a couple of minutes or multiple hours to handle.

1 Like