Bad shading in cube example

[erith835]

Thank you for providing rend3! I'm considering using it for a new non-game project where I want to combine my own custom graphics with standard models and nice looking shading, and it seems like rend3 perfectly fits my scope. However, I get a problem with the shading already in the simple cube example, running cargo run --bin cube (same problem in release mode). The problem is a bad and strange shading on the sides of the cube.

Here are my specs:
rend3 trunk pulled from github 2023-04-08 (release v0.3.0)
rust and cargo version 1.68.2
Windows 11 Home 10.0.22621
GeForce GTX 1650 (Display memory 3950 MB, Total Memory 12064 MB) Driver ver 31.0.15.3141, 2023-03-16
Core i5-12400F, 16 GB RAM

[aarroyoc]

I can confirm this happens to me also on Arch Linux using rustc/cargo 1.71.0-nightly on an integrated graphics card from an Intel Core i7-7500U