fix RPRMakie with Material (#3872)

* fix RPRMakie with Material

* revert example

RPRMakie/examples/bars.jl

@@ -8,21 +8,19 @@ radiance = 10000
 lights = [EnvironmentLight(0.5, load(RPR.assetpath("studio026.exr"))),
  PointLight(Vec3f(0, 0, 20), RGBf(radiance, radiance, radiance))]
 
-ax = LScene(fig[1, 1]; scenekw=(lights=lights,))
-Makie.axis3d!(ax.scene, Rect3f(Vec3f(0), Vec3f(1, 1, 1.2)))
+ax = LScene(fig[1, 1]; scenekw=(lights=lights, showaxis=false))
 rectMesh = FRect3D(Vec3f0(-0.5, -0.5, 0), Vec3f0(1))
 recmesh = GeometryBasics.normal_mesh(rectMesh)
 n = 100
 pos = [Point3f(i, j, 0) ./ 10 for i in 1:n for j in 1:n]
 z = rand(n, n)
-
 mat = (type=:Microfacet, color=:gray, roughness=0.2, ior=1.390)
-
 meshscatter!(ax, pos; marker=recmesh, markersize=Vec3f.(0.1, 0.1, z[:]), material=mat, color=vec(z))
 
 cam = cameracontrols(ax.scene)
 cam.eyeposition[] = Float32[5, 22, 12]
 cam.lookat[] = Float32[5, 5, -0.5]
 cam.upvector[] = Float32[0.0, 0.0, 1.0]
 cam.fov[] = 14.0
+
 @time display(ax.scene)

RPRMakie/src/meshes.jl

@@ -1,5 +1,5 @@
 function extract_material(matsys, plot)
- if haskey(plot, :material) && !isnothing(plot.material[])
+ if haskey(plot, :material) && !isnothing(to_value(plot.material))
  if plot.material isa Attributes
  return RPR.Material(matsys, Dict(map(((k,v),)-> k => to_value(v), plot.material)))
  else