When trying to render a video with the AppImage it crashes in some cases with libx264 not found. Probably this library needs to be added to the image as well. But this will require some debugging, since this library searched and loaded with in the ffmpeg code.

When I load the same URDF file using ROS and RBDL-Toolkit, their results are different? The URDF displayed by rBDL-Toolkit is incorrect. How can I solve this problem?
The urdf in ros rviz

The urdf in RBDL_toolkit

Hi, there. The work about these projects around rbdl is amazing, and i recently learn a lot .
I want to load the lua four link model with meshes created myself. The meshes of each frame is created from a STL file to an .obj file by blender, and the base coordiante of the STL file is exactly concide with the body frame of each body.
When i use the Meshup tool to load the lua model, everything goes fine, and the meshes showed right. However, when i use the rbdl-toolkit, the orientation of the meshbody is different. I dont know why.
I can solve this problem by adding rotaions of the object in lua file, but i thought it could be better load the file as same as the Meshup tool, cause the stl coordinate is designed right.
And what's more when i use rbdl-toolkit to load the human lua file created by ModelFactory with matlab, the result is not right, and when i use meshup tool, it works fine .

The lua file is as follows:
print("Lua: start Constructing four link_2")
l1=1 --1.0
l2=8 --8.0
l3=5 --6.0 why 5 will be calculated slow and maybe not right?
p_x0=5 --5.0
p_y0=3.0*0

print("Lua: Making the meshes")
meshes = {
link1 = {
color = { 1, 0, 0 },
--mesh_center = { 0, 0, 0 },
src = "link1.obj",
translate={0,0,0},
scale={1.5,1,1},
rotate={
axis={0,0,1},
angle=0,
}
},
link2 = {
color = { 0.3, 0.5, 0 },
--mesh_center = { 0, 0, 0 },
src = "link2.obj",
translate={0,0,0},
rotate={
axis={0,0,1},
angle=0,
}
},
link3 = {
dimensions = { 0.05, l3, 0.05 },
color = { 0, 0, 1 },
mesh_center = { 0, l3/2, 0 },
src = "unit_cube.obj",
},
}

inertiaMatrix = {
{5.0,0. ,0. },
{0. ,5.0,0. },
{0. ,0. ,5.0}
}
bodies = {
link1 = { mass = 1.0,
com = {0.0,l1/2,0.},
inertia = inertiaMatrix},
link2 = { mass = 3.,
com = {0.,l2/2,0.},
inertia = inertiaMatrix},
link3 = { mass = 3.,
com = {0.,l3/2,0.},
inertia = inertiaMatrix},
}

print("Lua: Making the model")
model = {
animation_settings = {
force_scale = 0.1,
torque_scale = 0.1,
force_color = {1., 1., 0.},
torque_color = {0., 1., 0.},
force_transparency = 0.25,
torque_transparency = 0.25,
--frames_scale=5,
},
gravity = {0., -9.81, 0.},
configuration = {
axis_front = { 1, 0, 0,},
axis_right = { 0, -1, 0,},
axis_up = { 0, 0, 1,},
},
constraint_sets = {
PinJoint = {
{constraint_type = "loop",
name = "x",
predecessor_body = "ROOT",
successor_body = "K3",
predecessor_transform = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {p_x0, p_y0, 0.000},
},
successor_transform = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {0.0, l3, 0.0,},
},
axis = {0, 0, 0, 1, 0, 0},
stabilization_coefficient = 1.0,
baumgarte_enabled = false,
},
{constraint_type = "loop",
name = "y",
predecessor_body = "ROOT",
successor_body = "K3",
predecessor_transform = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {p_x0, p_y0, 0.000},
},
successor_transform = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {0.0, l3, 0.0,},
},
axis = {0, 0, 0, 0, 1, 0},
stabilization_coefficient = 1.0,
baumgarte_enabled = false,
},
},
},
points = {
{name = "mass1",body = "K1",point = bodies.link1.com,},
{name = "mass2",body = "K2",point = bodies.link2.com,},
{name = "mass3",body = "K3",point = bodies.link3.com,},
--{name = "p1",body = "K2",point = {1,2,3},color={0,0,1},},
},
frames = {
{
name = "K1",
parent = "ROOT",
body = bodies.link1,
visuals = {meshes.link1},
joint = {{0.,0.,1.,0.,0.,0.}},
joint_frame = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {0, 0, 0.0},
},
-- points={
-- K1_p1={coordinates={1,2,3},color={0,1,0.5},draw_line=1,line_width=1,},
-- }
},
{
name = "K2",
parent = "K1",
body = bodies.link2,
visuals = {meshes.link2},
joint = {{0.,0.,1.,0.,0.,0.}},
joint_frame = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {0.,l1, 0.},
}
},
{
name = "K3",
parent = "K2",
body = bodies.link3,
visuals = {meshes.link3},
joint = {{0.,0.,1.,0.,0.,0.},},
joint_frame = {
E = {
{1, 0, 0},
{0, 1, 0},
{0, 0, 1},
},
r = {0.,l2, 0.},
}
},
},
}

return model

I built the rbdl-toolkit from source but the plugin are not loading. When i click on the plugin button it just turns blue and no menu appears showing the plugin. I have tested this both with the optimal on and off. Additionally, the setting under Toolkit menu shows nothing when it open up.

I am suing Qt 5.15.2 is this a problem? Is there a command line option i need to include?

Add Actions to Repositories -> needs packaging for rbdl

Starting a todo list of things that I think we will need to get Toolkit operating for regular HCRMI use at UW. I will summarize the current conversations regarding each of these issues, and we can create specific issues for them separately as needed. We can change this around as needed. If this should be moved elsewhere, I can do that as well.

Main goals:

• IK with URDF models

• Improve documentation

• Get RBDL Toolkit operational on Ubuntu 20.04

  • It sounds like AppImage might not play well on 20.04. This will need further testing
  • #13: "The AppImage was build using Ubuntu 18.04. According to the AppImage documention it should therefor run on anything newer. My Main system at home is using Arch and the it works just fine. But I also have seen previous versions of the toolkit AppImage fail on newer Ubuntu versions. Sadly debugging did not lead to a good explanation for why this happens and also the errors where not reproducible on a different machine with the same base operating system."
  • Slack with @ju6ge: "I would stick to 18.04 as the target for now because Canonical has been changing a lot of stuff in regards to their future vision about their packaging (they are pushing for snap packages). For now I think 18.04 is more stable."

• Generate basic wireframe on models that does not have explicit mesh information

  • Right now, Toolkit requires some mesh information to exist within the lua/urdf model before it visualizes anything. I think we should create some basic wireframe that draws straight lines between each tree node to serve as some basic visualization in cases that no meshes are found
  • #13: "Okay so the reemc_hd.lua is a valid lua model, but it does not specify any visuals, meaning there is no mesh information in there and therefor rbdl-toolkit has nothing to display"

• Create documentation on how to load Lua and URDF models @jfslin

  • Currently, no baseline documentation exists, so any sort of documentation will be helpful

• Load URDF models, including files created using Gazebo (ie REEM C from Docker) @jfslin

  • I haven't actually tried this yet, but if it works, it should be added to the Lua/URDF documentation

• Add ability to define ModelMarkers URDF information into the model via Toolkit @RVSagar

  • Most models will not have ModelMarker information within it, meaning we cannot IK with it
  • Might need to come up with a file format and notation just for this
  • Details: #14 (comment)

• Add marker names into GUI after a file (or model) is loaded

  • Slack with @ju6ge: "displaying marker names is not part of the code, but i think that would be a lot easier to add … to do that you would need to look into the implementation of the MotionMarkerPlugin, it implements creating the marker scene objects that get attached to the model. Qt3D should have functionalty to display text is some form or another, so you would need to attach a text object to the marker objects that get displayed, maybe even add a setting to enable displaying of the markers."

• Documentation

When I run rbdl-toolkit on a test model and file I get a linking error:

rbdl-toolkit: error while loading shared libraries: librbdl.so.3.0.0: cannot open shared object file: No such file or directory

I have just built the latest version of rbdl from the Orb-hd page, and the install folder contains librbdl.so.3.0.0. I suspect this is a CMakeLists error in rbdl-toolkit. Perhaps the custom rbdl directory is not being used to find the library? I'd check myself right now but I'm nearly out of time today.

cmake -DCUSTOM_QT_PATH=~/Qt/5.14.2/gcc_64 ..

-- Found RBDL: /usr/local/lib/librbdl.so
-- Found RBDL LUAMODEL: /usr/local/lib/librbdl_luamodel.so
-- Boost version: 1.65.1
CMake Error at CMakeLists.txt:175 (INSTALL):
  INSTALL TARGETS given no LIBRARY DESTINATION for shared library target
  "toolkitlib".


-- Configuring incomplete, errors occurred!
See also "~/Src/dynamicTools/rbdl-toolkit/build/CMakeFiles/CMakeOutput.log".

I tried loading the following double pendulum Lua model and was expecting to see the wireframe, but instead got a blank screen. No error messages shown.

Probably not urgent since the tutorial will show how to incorporate standard meshes so it's less of a concern, I think.

rod_length = 1

model = {
  gravity = { 0, -9.81, 0 },

  configuration = {
	axis_right = { 1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
  },

  frames = {
	{
	  name = "segment1",
	  parent = "ROOT",
	  visuals = { meshes.rod1 },
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	},
	{
	  name = "segment2",
	  parent = "segment1",
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		r = { 0., 0., -rod_length },
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	},
	{
	  name = "segment3",
	  parent = "segment1",
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		r = { 0., 0., rod_length },
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	}
  }
}

return model

Loading the proper meshes did provide the wireframe though:

rod_length = 1

meshes = {
  rod1 = {
	color = { 1, 0, 0},
	mesh_center = {0, 0, -rod_length/2},
	dimensions = { 0.1, 0.1, rod_length},
	src = "unit_cube.obj"
  },
  rod2 = {
	color = { 0, 1, 0},
	mesh_center = {0, 0, -rod_length/2},
	dimensions = { 0.1, 0.1, rod_length},
	src = "unit_cube.obj"
  }
}

model = {
  gravity = { 0, -9.81, 0 },

  configuration = {
	axis_right = { 1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
  },

  frames = {
	{
	  name = "segment1",
	  parent = "ROOT",
	  visuals = { meshes.rod1 },
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	},
	{
	  name = "segment2",
	  parent = "segment1",
	  visuals = { meshes.rod2 },
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		r = { 0., 0., -rod_length },
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	},
	{
	  name = "segment3",
	  parent = "segment1",
	  visuals = { meshes.rod2 },
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		r = { 0., 0., rod_length },
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	}
  }
}

return model

I am trying to build the core and optional plugins. If I set TOOLKIT_BUILD_CORE_PLUGINS and TOOLKIT_BUILD_OPTIONAL_PLUGINS to OFF, then it completes correctly. I have libunittest++-dev installed via apt. I installed catch2 via catchorg/Catch2#1383 (comment).

 CMAKE_BUILD_TYPE                                                                                                                                 
 CMAKE_INSTALL_PREFIX             /usr/local                                                                                                      
 CUSTOM_QT_PATH                   /home/jf2lin/Qt/5.15.2/gcc_64                                                                                   
 CUSTOM_RBDL_PATH                                                                                                                                 
 Catch2_DIR                       /usr/local/lib/cmake/Catch2                                                                                      
 Qt53DCore_DIR                    /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt53DCore                                                               
 Qt53DExtras_DIR                  /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt53DExtras                                                             
 Qt53DInput_DIR                   /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt53DInput                                                              
 Qt53DLogic_DIR                   /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt53DLogic                                                              
 Qt53DRender_DIR                  /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt53DRender                                                             
 Qt5Core_DIR                      /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt5Core                                                                 
 Qt5Gamepad_DIR                   /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt5Gamepad                                                              
 Qt5Gui_DIR                       /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt5Gui                                                                  
 Qt5Network_DIR                   /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt5Network                                                              
 Qt5Widgets_DIR                   /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt5Widgets                                                              
 Qt5_DIR                          /home/jf2lin/Qt/5.15.2/gcc_64/lib/cmake/Qt5                                                                     
 TOOLKIT_BUILD_CORE_PLUGINS       ON                                                                                                              
 TOOLKIT_BUILD_OPTIONAL_PLUGINS   ON                                                                                                              
 URDF_BUILD_TEST                  ON                                                                                                              
 UnitTest++_DIR                   UnitTest++_DIR-NOTFOUND                                                                                         

However, trying to compile this gives me the following:

CMake Warning at plugins/MotionMarkerPlugin/c3dfile/tests/CMakeLists.txt:11 (FIND_PACKAGE):
   By not providing "FindUnitTest++.cmake" in CMAKE_MODULE_PATH this project
   has asked CMake to find a package configuration file provided by
   "UnitTest++", but CMake did not find one.

   Could not find a package configuration file provided by "UnitTest++" with
   any of the following names:

     UnitTest++Config.cmake
     unittest++-config.cmake

   Add the installation prefix of "UnitTest++" to CMAKE_PREFIX_PATH or set
   "UnitTest++_DIR" to a directory containing one of the above files.  If
   "UnitTest++" provides a separate development package or SDK, be sure it has
   been installed.


 CMake Error at vendor/urdfparser/CMakeLists.txt:36 (ADD_EXECUTABLE):
   The target name "test" is reserved or not valid for certain CMake features,
   such as generator expressions, and may result in undefined behavior.


 CMake Error at vendor/urdfparser/CMakeLists.txt:37 (TARGET_LINK_LIBRARIES):
   Cannot specify link libraries for target "test" which is not built by this
   project.

I can't seem to find a unittest cmake file with my local unittest install, and couldn't find any resources online about it.

I've started some model documentation but I think someone will need to fill in same of the gaps.

@ju6ge do you have a working Lua and/or URDF model that only has 2-3 links so it's to read? I took the prosthesis model you sent me and cropped out only the right arm. It loads okay, so we could probably stick with that if needed.

It seems that the render request is never completed when using rbdl-toolkit on ubuntu. Maybe this is a bug with an older version of qt. Need to investigate further.

There are 2 edge cases where the camera movement breaks.

1. If you jump to the view from top and also jumped to side and front view previously all axis are perfectly alligned and camera movement just breaks. Jumping to the front or side view again, allows the camera to move again.

2. If you enter the orthographic view zooming does nothing anymore. This is due to the nature of orthographic drawing, but it would be nice if zooming in this mode would rescale the viewport.

Is there inverse dynamics functionality in toolkit?

As the title suggests, creating a model with an animation and attempting to render it results in a series of blank images.
The Qt library is writing:

QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined 

to the terminal window.

Source pulled as of Feb 13, 2021. Qt library: 5.15.2.

Hello,

I am having trouble building the package on my linux system. I followed the install instructions for Qt5 but I dont seem to have anything close to the path ~/Qt5.13/5.13.2/gcc_64

I have built and compiled QT5.15 with a parallel build folder. so I have the following folders

qt5/
qt5-build/

which were created by following the install instructions linked in your wiki. (https://wiki.qt.io/Building_Qt_5_from_Git#Getting_the_source_code)
What am I doing wrong?

Currently when a csv has a header line, it is expected that it has the same amount of columns as the rest of the file. This mostly is not the case when considering old meshup animation files and therefor we need to switch to another csv reader library or write our own.

For now throwing an error is sufficient since just removing the header from the file fixes the problem.

This is an interesting one. Using

rod_length = 1

meshes = {
  rod1 = {
	color = { 1, 0, 0},
	mesh_center = {0, 0, -rod_length/2},
	dimensions = { 0.2, 0.2, rod_length},
	src = "unit_cube.obj"
  }
}

model = {
  configuration = {
	axis_right = { 1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
  },

  frames = {
	{
	  name = "segment1",
	  parent = "ROOT",
	  visuals = { meshes.rod1 },
	  joint = {{ 0, 1, 0, 0, 0, 0 }},
	  joint_frame = {
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	}
  }
}

return model

and

0, 0
1, 1.57
2, 3.14
3, 4.73
4, 6.28

I get a normal looking render. However, if I change to E = {{1, 0, 0}, {0, -1, 0}, {0, 0, 1}}, not only does it not flip the axis rotation, the limb also flies into the screen. It looks like E doesn't like a flip from right hand rotations to left hand rotations.

I am trying to use rbdl-toolkit to perform IK, but have been unable to figure out how to proceed. I have separated this into 2 issues:

• Unable to load URDF models
• Unable to IK

Tried two different versions of rbdl-toolkit:

• rbdl-toolkit built using Ubuntu 20.04, QT 5.13.2
• rbdl-toolkit + plugins precompiled as AppImage

Working with 3 different models (2 of which should be working with rbdl-toolkit already):

• reemc_uw.urdf that I generated from the REEM C docker image using xacro
• reemc_hd.lua that I recieved from Heidelberg
• iCubHeidelberg01_no_weights.urdf that I received from Heidelberg

Trying built toolkit with the three model files:

jf2lin@HCRMIPC002:~/Downloads/rbdl$ rbdl-toolkit --model reemc_uw.urdf 
/usr/local/share/ORB/rbdl-toolkit

• Receives error: Error running file: /home/jf2lin/Downloads/rbdl/reemc_uw.urdf:1:unexpected symbol near '<'
• Result in rbdl-toolkit loading with no model

jf2lin@HCRMIPC002:~/Downloads/rbdl$ rbdl-toolkit --model iCubHeidelberg01_no_weights.urdf 
/usr/local/share/ORB/rbdl-toolkit

• Receives error: Error running file: /home/jf2lin/Downloads/rbdl/reemc_uw.urdf:1:unexpected symbol near '<'
• Result in rbdl-toolkit loading with no model

jf2lin@HCRMIPC002:~/Downloads/rbdl$ rbdl-toolkit --model reemc_hd.lua
/usr/local/share/ORB/rbdl-toolkit

• Receives no error
• Results in rbdl-toolkit loading with both the "grid" and the "reemc_hd" model on the sidebar, but no reem c model in the window. Clicking on the "grid" checkbox makes the grid disappear, but
• I can also load the lua model via the UI, but no figure show up either

Now trying the AppImage toolkit with the three model files:

jf2lin@HCRMIPC002:~/Downloads/rbdl$ ./rbdl-toolkit-x86_64.AppImage --model reemc_uw.urdf 
./rbdl-toolkit-x86_64.AppImage: symbol lookup error: /tmp/.mount_rbdl-teG56tS/usr/bin/../lib/libQt5Widgets.so.5: undefined symbol: _ZN22QGuiApplicationPrivate12addQtOptionsEP5QListI18QCommandLineOptionE, version Qt_5_PRIVATE_API
jf2lin@HCRMIPC002:~/Downloads/rbdl$ sudo !!
sudo ./rbdl-toolkit-x86_64.AppImage --model reemc_uw.urdf 
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
/tmp/.mount_rbdl-t9NrI3t/usr/local/share/ORB/rbdl-toolkit
Segmentation fault

• Result in no rbdl-toolkit loading

jf2lin@HCRMIPC002:~/Downloads/rbdl$ ./rbdl-toolkit-x86_64.AppImage --model reemc_hd.lua 
./rbdl-toolkit-x86_64.AppImage: symbol lookup error: /tmp/.mount_rbdl-t1h1gjT/usr/bin/../lib/libQt5Widgets.so.5: undefined symbol: _ZN22QGuiApplicationPrivate12addQtOptionsEP5QListI18QCommandLineOptionE, version Qt_5_PRIVATE_API
jf2lin@HCRMIPC002:~/Downloads/rbdl$ sudo ./rbdl-toolkit-x86_64.AppImage --model reemc_hd.lua 
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
/tmp/.mount_rbdl-tNSc0Or/usr/local/share/ORB/rbdl-toolkit

• Receives no error
• Results in rbdl-toolkit loading with both the "grid" and the "reemc_hd" model on the sidebar, but no reem c model in the window

jf2lin@HCRMIPC002:~/Downloads/rbdl$ sudo ./rbdl-toolkit-x86_64.AppImage --model iCubHeidelberg01_no_weights.urdf 
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
/tmp/.mount_rbdl-tl6pNDG/usr/local/share/ORB/rbdl-toolkit

• Receives error: Could not load the model! No file with filename: model://iCubHeidelberg01_model/dae_meshes/sim_chest__prt.dae found!

So it seems like the only workable option for me is the reemc_hd lua model, in both the compiled version as well as the AppImage version, but I'm guessing that no model showing up is a bit odd.

I am trying to use rbdl-toolkit to perform IK, but have been unable to figure out how to proceed. I have separated this into 2 issues:

• Unable to load URDF models
• Unable to IK

Using the rbdl-toolkit + plugins precompiled as AppImage, I was able to enable all the plug-ins, and was able to load a .c3d file. However, I get a missing model error instead (likely related to the missing model issue in #13):

I was also wondering if there was an existing guide on how to use the IK plugin? Thank you.

Hello. I would like to visualize the rbdl lib works with your tool kit.
As far as I followed your instruction, I am encountered an error after cloning source code.

Could not find a package configuration file provided by "Qt53DExtras" with
  any of the following names:

    Qt53DExtrasConfig.cmake
    qt53dextras-config.cmake```

Could you give me some instruction to resolve this?

1. Insert this line in the CMakeLists.txt file before the block of FIND_PACKAGE statements:

SET(CUSTOM_RBDL_PATH "" CACHE PATH "Path to specific RBDL Installation")

2. In the Toolkit->File menu I see two entries for 'Load Animation'

3. The arrow keys no longer move the camera position. If this is quick and easy to add, consider doing so.

4. With the mouse I can rotate, and I can pan. I don't know how to zoom, or walk forwards. How do I do this?

5. It's nice to have the option of seeing a solid floor. Though I suppose I can add this in the Lua file, so never mind!

@ju6ge a few questions from one of our student

1. A have a budget double pendulum working, but don't quite understand the joint specification. I understand that the 'joint_frame' entry is in terms of the parent's frame of reference, but how do you specify the joint location relative to the child or the child's center of mass? Or is it always at ( 0,0,0 ) for the child?
2. I noticed the example double pendulum uses constraints to pin the components together. Doesn't a joint already do that?
3. in the example double pendulum, both bodies are attached to the ROOT, shouldn't they be a kinetic chain ROOT->K1->K2? Or is that handled by the constraints?

Of course I wanted to try the fancy stuff out : )

When I set "TOOLKIT_BUILD_OPTIONAL_PLUGINS" to "On"

then CMake complains with the message:

CMake Error at plugins/RenderPlugin/CMakeLists.txt:35 (ADD_SUBDIRECTORY):
The source directory

 /home/mjhmilla/dev/orbGitHubCode/meshup2020/plugins/RenderPlugin/vendor/QVideoWriter

does not contain a CMakeLists.txt file.

Starting with a basic lua model, and a basic csv:

rod_length = 1

meshes = {
  rod1 = {
	color = { 1, 0, 0},
	mesh_center = {0, 0, -rod_length/2},
	dimensions = { 0.2, 0.2, rod_length},
	src = "unit_cube.obj"
  }
}

model = {
  configuration = {
	axis_right = { 1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
  },

  frames = {
	{
	  name = "segment1",
	  parent = "ROOT",
	  visuals = { meshes.rod1 },
	  joint = {{ 1, 0, 0, 0, 0, 0 }},
	  joint_frame = {
		E = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}
	  }
	}
  }
}

return model

0, 0
1, 1.57
2, 3.14
3, 4.73
4, 6.28

I was testing the directions of movement. Using this model as is, I was expecting the movement to be in the X rotation direction, but it does not. Here's a few examples.

Using

# correct, moving the positive x direction
	axis_right = { 1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
 joint = {{ 0, 0, 0, 1, 0, 0 }},

gives me a motion to the right-down direction, telling me that is the +X axis direction.

So I would expect the following

# incorrect, expecting counterclockwise movement
	axis_right = { 1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
 joint = {{ 1, 0, 0, 0, 0, 0 }},

to rotate by right hand rule around the +X direction. Instead, it incorrectly gives me the opposite motion:

The following are videos corresponding to flipping the axes direction by Z by 180 deg (so we are still respecting right hand rule global frame), as well as only mirroring the global X axis.

# correct, moving in the positive x direction
	axis_right = { -1, 0, 0 },
	axis_front = { 0, -1, 0 },
	axis_up =    { 0, 0, 1 },
 joint = {{ 0, 0, 0, 1, 0, 0 }},

# incorrect, expecting clockwise movement
	axis_right = { -1, 0, 0 },
	axis_front = { 0, -1, 0 },
	axis_up =    { 0, 0, 1 },
 joint = {{ 1, 0, 0, 0, 0, 0 }},

# correct, moving in the positive x direction
	axis_right = { -1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
 joint = {{ 0, 0, 0, 1, 0, 0 }},

# correct, moving CW
	axis_right = { -1, 0, 0 },
	axis_front = { 0, 1, 0 },
	axis_up =    { 0, 0, 1 },
 joint = {{ 1, 0, 0, 0, 0, 0 }},

On start application attempts to load an SVG file that is not present in the source tree.

ui_RenderImageDialog.h:108

icon.addFile(QString::fromUtf8("../../../../../../../usr/share/icons/Adwaita/scalable/places/user-desktop-symbolic.svg"), QSize(), QIcon::Normal, QIcon::Off);

Doesn't seem to impact the functionality as Qt fails somewhat gracefully and writes the error message to the terminal.

The IK produced by Puppeteer and RBDL produce different results. @RVSagar

Puppeteer:

Toolkit: