move to extension

Project.toml

@@ -7,12 +7,9 @@ version = "0.2.0"
 CoordinateTransformations = "150eb455-5306-5404-9cee-2592286d6298"
 DataInterpolations = "82cc6244-b520-54b8-b5a6-8a565e85f1d0"
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"
-Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
 JuliaSimCompiler = "8391cb6b-4921-5777-4e45-fd9aab8cb88d"
-LightXML = "9c8b4983-aa76-5018-a973-4c85ecc9e179"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MeshIO = "7269a6da-0436-5bbc-96c2-40638cbb6118"
-MetaGraphsNext = "fa8bd995-216d-47f1-8a91-f3b68fbeb377"
 ModelingToolkit = "961ee093-0014-501f-94e3-6117800e7a78"
 ModelingToolkitStandardLibrary = "16a59e39-deab-5bd0-87e4-056b12336739"
 Rotations = "6038ab10-8711-5258-84ad-4b1120ba62dc"
@@ -21,9 +18,15 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 
 [weakdeps]
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
+JuliaFormatter = "98e50ef6-434e-11e9-1051-2b60c6c9e899"
+LightXML = "9c8b4983-aa76-5018-a973-4c85ecc9e179"
+Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
+MetaGraphsNext = "fa8bd995-216d-47f1-8a91-f3b68fbeb377"
+
 
 [extensions]
 Render = ["Makie"]
+URDF = ["LightXML", "Graphs", "MetaGraphsNext", "JuliaFormatter"]
 
 [compat]
 CoordinateTransformations = "0.6"

docs/src/urdf.md

@@ -1,16 +1,16 @@
 # URDF import
 
 Multibody.jl supports import of [URDF files](https://wiki.ros.org/urdf) by means of the function [`urdf2multibody`](@ref).
-The functionality requires the user to install and load the packages LightXML.jl, Graphs.jl, MetaGraphs.jl and JuliaFormatter.jl, e.g.,
+The functionality requires the user to install and load the packages LightXML.jl, Graphs.jl, MetaGraphsNext.jl and JuliaFormatter.jl, e.g.,
 ```julia
 using Pkg
 Pkg.add([
  "LightXML",
  "Graphs",
- "MetaGraphs",
+ "MetaGraphsNext",
  "JuliaFormatter"
 ])
-using LightXML, Graphs, MetaGraphs, JuliaFormatter
+using Multibody, LightXML, Graphs, MetaGraphsNext, JuliaFormatter
 ```
 
 

ext/Project.toml

@@ -1,7 +1,11 @@
 [deps]
 CoordinateTransformations = "150eb455-5306-5404-9cee-2592286d6298"
+Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
+JuliaFormatter = "98e50ef6-434e-11e9-1051-2b60c6c9e899"
 JuliaSimCompiler = "8391cb6b-4921-5777-4e45-fd9aab8cb88d"
+LightXML = "9c8b4983-aa76-5018-a973-4c85ecc9e179"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
+MetaGraphsNext = "fa8bd995-216d-47f1-8a91-f3b68fbeb377"
 ModelingToolkit = "961ee093-0014-501f-94e3-6117800e7a78"
 Multibody = "e1cad5d1-98ef-44f9-a79a-9ca4547f95b9"
 OrdinaryDiffEq = "1dea7af3-3e70-54e6-95c3-0bf5283fa5ed"

ext/Render.jl

@@ -696,6 +696,9 @@ function rot_from_line(d)
  RotMatrix{3}([x y d])
 end
 
+Multibody.render!(scene, ::typeof(URDFRevolute), sys, sol, t) = false
+Multibody.render!(scene, ::typeof(URDFPrismatic), sys, sol, t) = false
+
 # ==============================================================================
 ## PlanarMechanics
 # ==============================================================================

src/Multibody.jl

@@ -103,6 +103,24 @@ A boolean indicating whether or not the component performed any rendering. Typic
 """
 function render! end
 
+"""
+ urdf2multibody(filename::AbstractString; extras=false, out=nothing, worldconnection = :rigid)
+
+Translate a URDF file into a Multibody model. Only available if LightXML.jl, Graphs.jl, MetaGraphs.jl and JuliaFormatter.jl are installed and loaded byt the user.
+
+Example usage:
+```
+urdf2multibody(joinpath(dirname(pathof(Multibody)), "..", "test/doublependulum.urdf"), extras=true, out="/tmp/urdf_import.jl")
+```
+
+## Keyword arguments
+- `extras=false`: If `true`, the generated code will include package imports, a simulation of the model and a rendering of the model.
+- `out=nothing`: If provided, the generated code will be written to this file, otherwise the string will only be returned.
+- `worldconnection=:rigid`: If `:rigid`, the world frame will be connected to the root link with a rigid connection. If a joint constructor is provided, this component will be instantiated and the root link is connected to the world through this, e.g., `worldconnection = FreeMotion`, `()->Prismatic(n=[0, 1, 0])` etc.
+"""
+function urdf2multibody end
+export urdf2multibody, URDFRevolute, URDFPrismatic
+
 const t = let
  (@independent_variables t)[1]
 end

src/joints.jl

@@ -805,4 +805,92 @@ end
  connect(revolute.frame_b, frame_b)
  end
 
+end
+
+@component function URDFRevolute(; name, r, R, axisflange = false, kwargs...)
+ if R == I(3) && r == zeros(3)
+ return j
+ end
+
+ systems = @named begin
+ frame_a = Frame()
+ frame_b = Frame()
+ rev = Revolute(; axisflange, kwargs...)
+ end
+ if R == I(3)
+ @named trans = FixedTranslation(; r, render=false)
+ else
+ R = RotMatrix{3}(R)
+ n = rotation_axis(R)
+ angle = rotation_angle(R)
+ @named trans = FixedRotation(; r, n, angle, render=false)
+ end
+ push!(systems, trans)
+ connections = [
+ connect(frame_a, trans.frame_a)
+ connect(trans.frame_b, rev.frame_a)
+ connect(rev.frame_b, frame_b)
+ ] 
+ if axisflange
+ more_systems = @named begin
+ axis = Rotational.Flange()
+ support = Rotational.Flange()
+ end
+ systems = [systems; more_systems]
+ connections = [
+ connections
+ connect(axis, rev.axis)
+ connect(support, rev.support)
+ ]
+ end
+ ODESystem(connections, t; systems, name)
+end
+
+@component function URDFPrismatic(; name, r, R, axisflange = false, kwargs...)
+ if R == I(3) && r == zeros(3)
+ return j
+ end
+
+ systems = @named begin
+ frame_a = Frame()
+ frame_b = Frame()
+ rev = Prismatic(; axisflange, kwargs...)
+ end
+ if R == I(3)
+ @named trans = FixedTranslation(; r, render=false)
+ else
+ R = RotMatrix{3}(R)
+ n = rotation_axis(R)
+ angle = rotation_angle(R)
+ @named trans = FixedRotation(; r, n, angle, render=false)
+ end
+ push!(systems, trans)
+ connections = [
+ connect(frame_a, trans.frame_a)
+ connect(trans.frame_b, rev.frame_a)
+ connect(rev.frame_b, frame_b)
+ ] 
+ if axisflange
+ more_systems = @named begin
+ axis = Rotational.Flange()
+ support = Rotational.Flange()
+ end
+ systems = [systems; more_systems]
+ connections = [
+ connections
+ connect(axis, rev.axis)
+ connect(support, rev.support)
+ ]
+ end
+ ODESystem(connections, t; systems, name)
+end
+
+@mtkmodel NullJoint begin
+ @components begin
+ frame_a = Frame()
+ frame_b = Frame()
+ end
+ @equations begin
+ connect(frame_a, frame_b)
+ end
 end