3D axis broken in GLMakie v0.10.13

[juliohm]

3D axis broken in GLMakie v0.10.13

[ffreyer]

Seems to be

Makie.jl/CairoMakie/src/primitives.jl

Lines 681 to 685 in 225d0ae

	Makie.clip_to_space(scene.camera, markerspace) *
	Makie.space_to_clip(scene.camera, space) *
	Makie.f32_convert_matrix(scene.float32convert, space) *
	model *
	to_ndim(Point4d, to_ndim(Point3d, p, 0), 1)

If you add a parenthesis that include at least model * to_ndim(...) things work. Without them *(a, b, c, xs...) from Base runs, with
*(A::AbstractMatrix, B::AbstractMatrix, C::AbstractMatrix, x::AbstractVector) from LinearAlegbra. The former does a foldl, i.e. it multiplies the first two matrices first, the latter goes right to left. And the first two matrices are risky in terms of Float32 precision

WGLMakie computes the matrix product of the first two matrices directly as well, but in Javascript. I'm guessing it uses double precision.

Going left to right is quite a bit faster on it's own (14.9ns vs 20.7ns) and also useful for optimizing projections like [M1 * M2 * p for p in ps] to T = M1 * M2; [T * p for p in ps], so I think it would be best to just replace the camera matrices with Mat4d and convert to Mat4f as late as possible.

[asinghvi17]

Is this common across all backends, and do you have an MWE?

[juliohm]

Data: https://gist.github.com/juliohm/ca6ddae1995a5916c987282875ccadae

MWE:

using GLMakie
using DelimitedFiles

X = readdlm("data.csv", ',')

xyz = Tuple.(eachrow(X))

scatter(xyz)

[asinghvi17]

I can replicate this on GLMakie and CairoMakie, but WGLMakie seems to give the correct result.

[asinghvi17]

GLMakie

CairoMakie

WGLMakie

[ffreyer]

This is not a new issue. I checked Makie 0.21, 0.20 and 0.19 and they all have it. Weird that it's backend specific...

[asinghvi17]

Could this be a float precision issue then? The numbers are in that range...

[ffreyer]

Probably, but why is it not happening in WGLMakie?