extract default scene creation into function

ext/Render.jl

@@ -32,6 +32,22 @@ function get_systemtype(sys)
 end
 
 
+function default_scene(x,y,z,R; F = false)
+ if string(Makie.current_backend()) == "CairoMakie"
+ scene = Scene() # https://github.com/MakieOrg/Makie.jl/issues/3763
+ fig = nothing
+ else
+ fig = Figure()
+ # scene = LScene(fig[1, 1], scenekw = (lights = [DirectionalLight(RGBf(1, 1, 1), Vec3f(-1, 0, 0))],)).scene # This causes a black background for CairoMakie, issue link above
+ scene = LScene(fig[1, 1]).scene
+ end
+ cam3d!(scene)
+ scene.camera.view[] = [
+ R [x,y,z]; 0 0 0 1
+ ]
+ scene, fig
+end
+
 
 function render(model, sol,
  timevec::Union{AbstractVector, Nothing} = nothing;
@@ -42,23 +58,14 @@ function render(model, sol,
  R = I(3),
  timescale = 1.0,
  filename = "multibody_$(model.name).mp4",
+ scene = default_scene(x,y,z,R)[1],
+ kwargs...
  )
  if timevec === nothing
  timevec = range(sol.t[1], sol.t[end]*timescale, step=1/framerate)
  end
  # with_theme(theme_dark()) do
- if string(Makie.current_backend()) == "CairoMakie"
- scene = Scene() # https://github.com/MakieOrg/Makie.jl/issues/3763
- else
- fig = Figure()
- scene = LScene(fig[1, 1], scenekw = (lights = [DirectionalLight(RGBf(1, 1, 1), Vec3f(-1, 0, 0))],)).scene # This causes a black background for CairoMakie, issue link above
- end
-
- cam3d!(scene)
- scene.camera.view[] = [
- R [x,y,z]; 0 0 0 1
- ]
- t = 0.0
+
  t = Observable(timevec[1])
 
  recursive_render!(scene, complete(model), sol, t)
@@ -74,22 +81,16 @@ function render(model, sol, time::Real;
  kwargs...,
  )
 
- fig = Figure()
- scene = LScene(fig[1, 1]).scene
- cam3d!(scene)
+ # fig = Figure()
+ # scene = LScene(fig[1, 1]).scene
+ # cam3d!(scene)
+ scene, fig = default_scene(0,0,-10,I(3))
  # mesh!(scene, Rect3f(Vec3f(-5, -3.6, -5), Vec3f(10, 0.1, 10)), color=:gray) # Floor
 
  steps = range(sol.t[1], sol.t[end], length=3000)
 
  t = Slider(fig[2, 1], range = steps, startvalue = time).value
 
- scene.camera.view[] = [
- 1 0 0 0
- 0 1 0 0
- 0 0 1 -10
- 0 0 0 1
- ]
-
  recursive_render!(scene, complete(model), sol, t)
  fig, t
 end
@@ -112,9 +113,9 @@ end
 render!(scene, ::Any, args...) = false # Fallback for systems that have no rendering
 
 function render!(scene, ::typeof(Body), sys, sol, t)
- r_cm = collect(sys.r_cm)
+ r_cmv = collect(sys.r_cm)
  thing = @lift begin # Sphere
- r_cm = sol($t, idxs=r_cm)
+ r_cm = sol($t, idxs=r_cmv)
  Ta = get_frame(sol, sys.frame_a, $t)
  coords = (Ta*[r_cm; 1])[1:3] # TODO: make use of a proper transformation library instead of rolling own?
  point = Point3f(coords)
@@ -127,12 +128,12 @@ function render!(scene, ::typeof(Body), sys, sol, t)
  end
  mesh!(scene, thing, color=:purple)
 
- iszero(sol(0.0, idxs=collect(r_cm))) && (return true)
+ iszero(sol(0.0, idxs=r_cmv)) && (return true)
 
  thing = @lift begin # Cylinder
  Ta = get_frame(sol, sys.frame_a, $t)
 
- r_cm = sol($t, idxs=r_cm) # r_cm is the center of the sphere in frame a
+ r_cm = sol($t, idxs=r_cmv) # r_cm is the center of the sphere in frame a
  iszero(r_cm)
  coords = (Ta*[r_cm; 1])[1:3]
  point = Point3f(coords) # Sphere center in world coords