Fix transforming surface normals

[singularitti]

Description

Fixes #3702

As discussed in issue #3702, under the guidance of @kbarros, we made changes that solve the incorrect shading of ellipsoid surfaces of markers under light, displaying spherical reflections (mathematical formulae stated in #3702). The following figures show examples before and after this change. Please note that we are not experts in the GLSL language, so you may want to double-check whether this change may break some code. If you need changes to other backends, I am happy to help.

Testing code snippet:

using CairoMakie
# using GLMakie
# using WGLMakie
pts = Point3f[[0,0,0], [1,0,0]]
markersize = Vec3f[[0.5, 0.2, 0.5], [0.5, 0.2, 0.5]]
rotations = [qrotation(Vec3f(1,0,0), 0), qrotation(Vec3f(1,1,0), π/4)]
meshscatter(pts; markersize, rotations, color=:yellow)

CairoMakie

Before

After

GLMakie

Before

After

WGLMakie

Before

After

Type of change

Delete options that do not apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• Added an entry in CHANGELOG.md (for new features and breaking changes)
• Added or changed relevant sections in the documentation
• Added unit tests for new algorithms, conversion methods, etc.
• Added reference image tests for new plotting functions, recipes, visual options, etc.

[ffreyer]

Thanks for the pr.

Since none of the refimg tests are failing we should add a new one here. It would probably be good to use more extreme shading like color=:white, diffuse = Vec3f(-2, 0, 4), specular = Vec3f(4, 0, -2) to make the differences more obvious. Otherwise the test image comparison may struggle to pick up on it. The test would go in here: https://github.com/MakieOrg/Makie.jl/blob/master/ReferenceTests/src/tests/examples3d.jl

Other than that this just needs an entry in https://github.com/MakieOrg/Makie.jl/blob/master/CHANGELOG.md

[jkrumbiegel]

Otherwise the test image comparison may struggle to pick up on it.

Thankfully the image comparison is a lot more sensitive nowadays, but it's still good practice to make failure modes as obvious as possible

[singularitti]

Done! Please have a look @ffreyer @jkrumbiegel:

Before fixing rotations

After fixing rotations

CairoMakie

GLMakie

WGLMakie