Render artifacts when a model self-intersected more than twice

[Askaniy]

Artifacts when a model self-intersects more than twice.
Probable was also seen on Phobos by NGTS addict / thelostprobe here.

• OS: Linux, openSUSE Tumbleweed
• Frontend: Qt5, Wayland
• Version: 1.7.0, at least bed2d96 — 7f97b84

[munix9]

hm, lgtm, maybe it depends on the hardware.
or have you made special settings?

[Askaniy]

I tested on a laptop with Intel graphics (currently unavailable until tomorrow, battery issues) and PC with Radeon graphics. There were no special settings and no modifications

[munix9]

More details from my side:
tested on two notebooks, each with the same openSUSE Tumbleweed and there are no artifacts.

openSUSE Tumbleweed 20230819

$ inxi --graphics

Graphics:
  Device-1: Intel 3rd Gen Core processor Graphics driver: i915 v: kernel
  Display: x11 server: X.Org v: 21.1.8 with: Xwayland v: 23.1.2 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: crocus gpu: i915
    resolution: 1920x1080~60Hz
  API: OpenGL v: 4.2 Mesa 23.1.5 renderer: Mesa Intel HD Graphics 4000 (IVB
    GT2)

Graphics:
  Device-1: Intel Alder Lake-P Integrated Graphics driver: i915 v: kernel
  Device-2: Chicony USB2.0 Camera driver: uvcvideo type: USB
  Display: x11 server: X.Org v: 21.1.8 with: Xwayland v: 23.1.2 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: i915
    resolution: 1920x1080~60Hz
  API: OpenGL v: 4.6 Mesa 23.1.5 renderer: Mesa Intel Graphics (ADL GT2)

The output of
$ sudo zypper se -si *celestia* *meshopt*
would also be interesting (if it is a package installation),

[Askaniy]

  Device-1: AMD Navi 22 [Radeon RX 6700/6700 XT/6750 XT / 6800M/6850M XT]
    driver: amdgpu v: kernel
  Display: wayland server: X.org v: 1.21.1.8 with: Xwayland v: 23.1.2
    compositor: kwin_wayland driver: X: loaded: modesetting unloaded: fbdev,vesa
    dri: radeonsi gpu: amdgpu resolution: 3440x1440
  API: OpenGL v: 4.6 Mesa 23.1.5 renderer: AMD Radeon RX 6700 XT (navi22
    LLVM 16.0.6 DRM 3.52 6.4.9-1-default)

S  | Name                         | Type  | Version                         | Arch   | Repository
---+------------------------------+-------+---------------------------------+--------+-------------------------------------------
i+ | celestia                     | пакет | 1.7.0~git20230818+eb1cb28-802.1 | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i  | celestia-common              | пакет | 1.7.0~git20230818+eb1cb28-802.1 | noarch | home:munix9:unstable (openSUSE_Tumbleweed)
i  | celestia-data                | пакет | 1.7.0~git20230807+4b07c07-95.1  | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i  | celestia-data-avif           | пакет | 1.7.0~git20230807+4b07c07-34.3  | noarch | home:munix9:unstable (openSUSE_Tumbleweed)
i  | celestia-data-lang           | пакет | 1.7.0~git20230807+4b07c07-95.1  | noarch | home:munix9:unstable (openSUSE_Tumbleweed)
i+ | celestia-lang                | пакет | 1.7.0~git20230818+eb1cb28-802.1 | noarch | home:munix9:unstable (openSUSE_Tumbleweed)
i  | celestia-qt5                 | пакет | 1.7.0~git20230818+eb1cb28-802.1 | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i+ | celestia-qt6                 | пакет | 1.7.0~git20230818+eb1cb28-802.1 | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i  | libcelestia1_7               | пакет | 1.7.0~git20230818+eb1cb28-802.1 | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i  | libcelestia1_7-x86-64-v3     | пакет | 1.7.0~git20230818+eb1cb28-802.1 | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i  | libmeshoptimizer2d           | пакет | 0.19-4.4                        | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)
i  | libmeshoptimizer2d-x86-64-v3 | пакет | 0.19-4.4                        | x86_64 | home:munix9:unstable (openSUSE_Tumbleweed)```

[munix9]

Ah, you are using the converted avif images, that could be the problem - at least it is the difference with my setup.

I will test and report.

[munix9]

The problem is reproducible and is probably related to converted images.

Whether this is due to the avif implementation or the conversion of the images, I can not say, the problem is reproducible with the AppImage version of celestia, which contains the avif images for storage space reasons.

Tested with celestia-1.7.0~git20230820+bed2d96-lp154.1.1.Build1.1.glibc2.17-x86_64.AppImage

See https://download.opensuse.org/repositories/home:/munix9:/unstable/AppImage/

[munix9]

The converted image medres/arrokoth.avif actually looks good, I can't see any visual abnormalities to the original medres/arrokoth.jpg.

$ mediainfo arrokoth.*

General
Complete name                            : arrokoth.avif
Format                                   : avif
Codec ID                                 : avif (avif/mif1/miaf/MA1A)
File size                                : 94.4 KiB

Image
ID                                       : 1
Format                                   : av01
Codec ID                                 : av01
Width                                    : 2 048 pixels
Height                                   : 1 024 pixels
Color space                              : YUV
Bit depth                                : 8 bits
Stream size                              : 84.5 KiB (89%)
Matrix coefficients                      : BT.601
Color range                              : Full
Describes                                : 2,3
Codec configuration box                  : av1C

General
Complete name                            : arrokoth.jpg
Format                                   : JPEG
File size                                : 308 KiB

Image
Format                                   : JPEG
Width                                    : 2 048 pixels
Height                                   : 1 024 pixels
Color space                              : YUV
Chroma subsampling                       : 4:4:4
Bit depth                                : 8 bits
Compression mode                         : Lossy
Stream size                              : 308 KiB (100%)
ColorSpace_ICC                           : RGB

[munix9]

I have built celestia without meshoptimizer for testing and now things look better.
There are still slight artifacts visible with avif images.

celestia without meshoptimizer for openSUSE Leap 15.4
https://download.opensuse.org/repositories/home:/munix9:/test/15.4/x86_64/

celestia without meshoptimizer as AppImage based on the above mentioned version for Leap 15.4
https://download.opensuse.org/repositories/home:/munix9:/test/AppImage/

Summary:
celestia with avif images and without meshoptimizer has slight artifacts.
celestia with avif images and with meshoptimizer has significant artifacts.

[Askaniy]

Changed configuration, bug is still there.

Graphics:
  Device-1: AMD Cezanne [Radeon Vega Series / Radeon Mobile Series]
    driver: amdgpu v: kernel
  Display: wayland server: X.org v: 1.21.1.8 with: Xwayland v: 23.2.0
    compositor: kwin_wayland driver: X: loaded: modesetting unloaded: fbdev,vesa
    dri: radeonsi gpu: amdgpu resolution: 3440x1440
  API: OpenGL v: 4.6 Mesa 23.1.6 renderer: AMD Radeon Graphics (renoir LLVM
    16.0.6 DRM 3.52 6.4.12-1-default)

A more precise description of the bug: artifacts when a model self-intersected more than twice.
Probable was also seen on Phobos by NGTS addict / thelostprobe here.

[375gnu]

A more precise description of the bug: artifacts when a model self-intersected more than twice.

That explains why the bug disappears without meshoptimizer.

[munix9]

Is there anything I can specify when converting the images or is it in the processing of avif images in celestia?

Because as far as I know the problem only occurs with avif.

[375gnu]

Maybe it makes sense not to convert affected textures to avif? And also we need a parameter to disable meshoptimizer on per-object basis.

[munix9]

Maybe it makes sense not to convert affected textures to avif? And also we need a parameter to disable meshoptimizer on per-object basis.

Maybe. I'm also considering delivering only the original medres images in the appimage as an alternative.