Strange black line artifact in the screen over large plane mesh at specific camera views.

[GustJc]

Tested versions

• Reproducible in v4.7.stable.mono.official [5b4e0cb]

System information

Godot v4.7.stable.mono - Windows 10 (build 17134) - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1070 (NVIDIA; 31.0.15.3141) - Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz (8 threads) - 23.92 GiB memory - WASAPI (96000 Hz, Stereo/mono)

Issue description

While running the game, there seems to be a clearly visible black line on top of the plane mesh.

This only happens at very specific camera position and angles and with non standard resolutions.

My guess is that it is some sort of precision error.

strange.line.mp4

Changing the camera position even a bit makes it go away.

I found this artifact by pure luck. But as it was my default testing camera, I saw it every time.

Increasing the size of the plane slightly or changing the subdivision can affect this or make this go away entirely.

strange.line.2.mp4

The material and the texture does not seem to affect this line artifact.
Similarly, changing the texture filter and compression also have zero effects.

strange.line.textured.mp4

Steps to reproduce

Its better to use the MRP;
It's a bit hard to replicate due to very specific conditions. But here are the steps:

(The values need to be the exact ones to ensure this bug show up)

1. Create a new 3D scene with a plane mesh of size 250 x 250
2. Create a 3D node with a camera child
3. Set the camera position to (0, 10, 0)
4. Change the camera parent rotation to -45 y
5. Add environment & light and play the game.
6. Drag and scale the screen (you can set res override to 1223 x 687 for a know bad one)

Result: Black line artifact appears over the play
Expected: No line artifact

Minimal reproduction project (MRP)

Black Line Artifact Plane (MRP).zip

The basic.tscn scene is the one created from the steps instructions, with the camera already in the "bad position".