# Animation with Meshes.jl
**URL:** https://discourse.julialang.org/t/animation-with-meshes-jl/124618
**Category:** General Usage
**Created:** [January 10, 2025, 1:41am UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618 "2025-01-10T01:41:40Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Mizu49](https://discourse.julialang.org/u/Mizu49)
#### Post date: [January 10, 2025, 1:41am UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/1 "2025-01-10T01:41:40Z")
How can I animate the Box defined by Meshes.jl?
I thought the following code might work.
```julia
using GLMakie, Meshes, Rotations
b = Meshes.Box((-1, -1, -1), (1, 1, 1))
obs_b = Observable(b)
fig = Figure(size = (800, 500))
ax = Axis3(
fig[1, 1],
)
hidespines!(ax)
hidedecorations!(ax)
Meshes.viz(obs_b)
record(fig, "animation.gif", framerate = 20) do idx
# update observables
obs_b[] = b |> Rotate(AngleAxis(0.2, 1.0, 0.0, 0.0))
end
```
However, this gives an error:
```julia
ERROR: MethodError: Cannot `convert` an object of type TransformedGeometry{πΌ{3}, CoordRefSystems.Cart
esian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), Unitful.FreeUnits{(Unitful.Unit{:Meter, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}()}(0, 1//1),), Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), nothing}}}, Meshes.Box{πΌ{3}, CoordRefSystems.Cartesian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, Unitful.Dim
ensions{(Unitful.Dimension{:Length}(1//1),)}(), Unitful.FreeUnits{(Unitful.Unit{:Meter, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}()}(0, 1//1),), Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), nothing}}}}, Rotate{AngleAxis{Float64}}} to an object of type Meshes.Box{πΌ{3}, CoordRef
Systems.Cartesian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), Unitful.FreeUnits{(Unitful.Unit{:Meter, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}()}(0, 1//1),), Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), nothing}}}}
The function `convert` exists, but no method is defined for this combination of argument types.
```
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [January 10, 2025, 12:25pm UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/2 "2025-01-10T12:25:03Z")
Hi @Mizu49 , please tag the question with `meshes` or post it in the `Geo` category of this forum, otherwise we donβt get a notification.
To answer your question, notice that the rotation of an axis-aligned `Box` is no longer an axis-aligned box, but a `TransformedBox`:
```julia
julia> b |> Rotate(AngleAxis(0.2, 1.0, 0.0, 0.0))
TransformedBox
ββ geometry: Box(min: (x: -1.0 m, y: -1.0 m, z: -1.0 m), max: (x: 1.0 m, y: 1.0 m, z: 1.0 m))
ββ transform: Rotate(rot: [1.0 0.0 0.0; 0.0 0.980067 -0.198669; 0.0 0.198669 0.980067])
```
This means that your `Observable` must hold any type of `Geometry`, not just `Box`. You can solve the issue by defining:
```julia
obs_b = Observable{Any}(b)
```
There is another issue in your code where you update the observable with a constant, instead of with the current value of the observable.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [January 10, 2025, 12:33pm UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/3 "2025-01-10T12:33:46Z")
> [@Mizu49](#):
>
> ```julia
> ERROR: MethodError: Cannot `convert` an object of type TransformedGeometry{πΌ{3}, CoordRefSystems.Cart
> esian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), Unitful.FreeUnits{(Unitful.Unit{:Meter, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}()}(0, 1//1),), Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), nothing}}}, Meshes.Box{πΌ{3}, CoordRefSystems.Cartesian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, Unitful.Dim
> ensions{(Unitful.Dimension{:Length}(1//1),)}(), Unitful.FreeUnits{(Unitful.Unit{:Meter, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}()}(0, 1//1),), Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), nothing}}}}, Rotate{AngleAxis{Float64}}} to an object of type Meshes.Box{πΌ{3}, CoordRef
> Systems.Cartesian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), Unitful.FreeUnits{(Unitful.Unit{:Meter, Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}()}(0, 1//1),), Unitful.Dimensions{(Unitful.Dimension{:Length}(1//1),)}(), nothing}}}}
> The function `convert` exists, but no method is defined for this combination of argument types.
>
> ```
This error message is telling you that the `Observable` of `Box` cannot hold a `TransformedGeometry`. The error message could have been clearer though given that this is a common pattern with `Observable`.
---
### Author:  [@Mizu49](https://discourse.julialang.org/u/Mizu49)
#### Post date: [January 11, 2025, 2:59am UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/4 "2025-01-11T02:59:47Z")
@juliohm
Thank you for your comments!
I still have trouble with the following updated codeβ¦
```julia
using GLMakie, Meshes, Rotations
b = Meshes.Box((-1, -1, -1), (1, 1, 1))
obs_b = Observable{Any}(b)
fig = Figure(size = (800, 500))
ax = Axis3(
fig[1, 1],
)
hidespines!(ax)
hidedecorations!(ax)
Meshes.viz(obs_b)
framerate = 30
timestamps = range(0, 2, step=1/framerate)
record(fig, "animation.gif", timestamps, framerate = framerate) do idx
# update observables
obs_b[] = obs_b[] |> Rotate(AngleAxis(0.2, 1.0, 0.0, 0.0))
end
```
`obs_b[] = obs_b[] |> Rotate(AngleAxis(0.2, 1.0, 0.0, 0.0))` gives an error.
```julia
ERROR: MethodError: Cannot `convert` an object of type
GeometrySet{πΌ {3},CoordRefSystems.Cartesian{CoordRefSystems.NoDatum,3,Unitful.Quantity{Float64,π ,Unitful.FreeUnits{(m,),π ,nothing}}},TransformedGeometry{πΌ{3}, CoordRefSystems.Cartesian3D{CoordRefSyst
ems.NoDatum, Unitful.Quantity{Float64, π, Unitful.FreeUnits{(m,), π, nothing}}}, Meshes.Box{πΌ{3}, C
oordRefSystems.Cartesian3D{CoordRefSystems.NoDatum, Unitful.Quantity{Float64, π, Unitful.FreeUnits{(m
,), π, nothing}}}}, Rotate{AngleAxis{Float64}}} } to an object of type
GeometrySet{πΌ {3},CoordRefSystems.Cartesian{CoordRefSystems.NoDatum,3,Unitful.Quantity{Float64,π ,Unitful.FreeUnits{(m,),π ,nothing}}},Meshes.Box{πΌ{3}, CoordRefSystems.Cartesian3D{CoordRefSystems.NoDat
um, Unitful.Quantity{Float64, π, Unitful.FreeUnits{(m,), π, nothing}}}} }
The function `convert` exists, but no method is defined for this combination of argument types.
```
I believe the type convertion still not working with the Geometry and Observables.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [January 11, 2025, 9:15am UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/5 "2025-01-11T09:15:35Z")
Hi @Mizu49, the code looks fine to me. Could you try with a Triangle geometry instead to see if this issue is specific to Box?
---
### Author:  [@Mizu49](https://discourse.julialang.org/u/Mizu49)
#### Post date: [January 13, 2025, 12:33pm UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/6 "2025-01-13T12:33:29Z")
Hi @juliohm ,
I tried with the `Triangle` geometry, and it looks file to me.
```julia
using GLMakie, Meshes, Rotations
geometry = Triangle((0, 0), (1, 0), (0, 1))
obs = Observable{Any}(geometry)
fig = Figure()
ax = Axis(
fig[1, 1],
limits = tuple(-1, 1, -1, 1)
)
Meshes.viz!(obs)
iter = 1:100
record(fig, "animation.gif", iter, framerate = 30) do idx
# update observables
obs[] = obs[] |> Rotate(0.2)
end
```
Result:
Iβm not sure why this code doesnβt work for `Box` geometryβ¦
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [January 13, 2025, 1:59pm UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/7 "2025-01-13T13:59:06Z")
`Box` is a primitive geometry for which we have various optimizations. These optimizations may be interfering with `viz` dispatch methods. Could you please file an issue on GitHub so that we can take a look at it?
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [January 13, 2025, 8:44pm UTC](https://discourse.julialang.org/t/animation-with-meshes-jl/124618/8 "2025-01-13T20:44:52Z")
@Mizu49 in the meantime, you can use `quad = convert(Quadrangle, box)` to produce the animation. The `Quadrangle` can be rotated without issues.
If your box is 3D, then you can use `hexa = convert(Hexahedron, box)`.
The error message above indicates that somewhere in the code the `TransformedBox` is saved in a variable that holds a `Box`.