3D Camera glitches with WGLMakie, not with GLMakie

[xlxs4]

• [x] are you running newest version (version from docs) ?
• [x] can you reproduce the bug with a fresh environment ? (]activate --temp; add Makie)

• [x] What platform + GPU are you on?

  ```julia julia> versioninfo() Julia Version 1.10.3 Commit 0b4590a5507 (2024-04-30 10:59 UTC) Build Info: Official https://julialang.org/ release Platform Info: OS: macOS (arm64-apple-darwin22.4.0) CPU: 10 × Apple M2 Pro WORD_SIZE: 64 LIBM: libopenlibm LLVM: libLLVM-15.0.7 (ORCJIT, apple-m1) Threads: 6 default, 0 interactive, 3 GC (on 6 virtual cores) ```

using Pkg

pkg"activate --temp"
pkg"add GLMakie WGLMakie"

using LinearAlgebra

# using GLMakie
using WGLMakie

function center!(translate_to, ls, cam)
    current_look_direction = normalize(cam.lookat[] - cam.eyeposition[])
    desired_distance = norm(cam.eyeposition[] - cam.lookat[])

    cam.lookat[] = translate_to
    cam.eyeposition[] = translate_to - current_look_direction * desired_distance

    Makie.update_cam!(ls.scene)
    return nothing
end

function init()
    backend = Makie.current_backend()
    backend.activate!()

    fig = Figure(; backgroundcolor=:black)

    ls = LScene(fig[1, 1]; show_axis=false)
    cam = cam3d!(ls.scene; center=false)
    vertices = [
        0.0 0.0
        1.0 0.0
        1.0 1.0
        0.0 1.0
    ]
    faces = [
        1 2 3
        3 4 1
    ]
    m = mesh!(ls, vertices, faces)
    return fig, ls, cam, m
end

fig, ls, cam, m = init()

fig

for _ in 1:1000
    pos = Vec3f(normalize(rand(Float32, 3)))
    translate!(m, pos)
    center!(pos, ls, cam)
    sleep(0.01)
end

https://github.com/MakieOrg/Makie.jl/assets/54778816/8fd9fb23-fdab-414d-b9e1-63e1adfed45f

[xlxs4]

Could it be related to https://github.com/MakieOrg/Makie.jl/issues/1454?

[SimonDanisch]

Would it be possible to make an example, that's less glitchy in itself? 😅 It seems like the expected result is that nothing happens, even though the camera is moved? For me nothing appens in WGLMakie and GLMakie, so not sure if I'm not able to reproduce it, or if the glitch is really short. I don't really understand the example, which makes it harder to debug... Does e.g. rotating around an object glitch too?

[ffreyer]

Isn't this just a consequence of WGLMakie being more asynchronous? I.e. WGLMakie is processing some of the events/messages here, rendering, then processing the rest?

[SimonDanisch]

It could be, but that's why I want to nail down the problem, which is not that easy with this example.

[xlxs4]

I understand the example isn't very helpful. I tried to make a MWE centered around the actual offending function in my code (center!). Yes, the expected result is you keep seeing exactly the same, since the camera updates to follow the mesh. Here's what actually prompted me to open the issue:

GLMakie:

WGLMakie:

I can try to come up with a different example, but then who's to tell if the glitch there has the same cause with the one due to center!? If you have any advice on what kind of example I should come up with, do tell!

[SimonDanisch]

Woah that looks really cool :) I think that example shows quite clearly that it's update related... Can you try throttling the updates? Will not look nice I guess, but if the problem is that update get too many, it should at least stop stuttering

[xlxs4]

Thanks! The stuttering is still there:

https://github.com/MakieOrg/Makie.jl/assets/54778816/840a2bb7-adc7-4088-8445-88dfd1104d74