ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange
Ask Your Question
0

Problems working with .dae files

asked 2017-11-28 12:12:42 -0500

SteBisi gravatar image

updated 2017-11-29 04:08:26 -0500

gvdhoorn gravatar image

Hello everyone, I'm struggling with a urdf model to visualize in rviz, this is the file I've written so far:

<?xml version="1.0"?>
<robot name="bot2489">

  <material name="black">
    <color rgba = "0 0 0 1"/>
  </material>

  <link name="base_link">
    <visual>
      <origin rpy="0.0 0 0" xyz="0 0 0"/>
      <material name="black"/>
      <geometry>
        <mesh filename="package://bot2489_description/meshes/bot2489_body.dae"/>
      </geometry>
    </visual>
    <collision>
      <origin rpy="0.0 0 0" xyz="0 0 0"/>
      <geometry>
        <mesh filename="package://bot2489_description/meshes/bot2489_body.dae"/>
      </geometry>
    </collision>
  </link>
</robot>

The problem is that when I launch it in rviz, using the urdf_tutorial display.launch file, nothing appears. In the "Global Status" section of the window there's a warning :

No tf data. Actual error: Fixed Frame [base_link] does not exist

It is weird, because the .dae file should be fine (is made with Rhino v5 and saved as .dae), and on the terminal, while loading the file, I get no errors. Can you please help me to understand what I'm doing wrong?

edit retag flag offensive close merge delete

Comments

Can you update your question text with the exact command that you use to start everything (ie: the one with display.launch) and include the complete output you see on the console after starting it?

gvdhoorn gravatar image gvdhoorn  ( 2017-11-29 04:10:22 -0500 )edit

If you posted your complete URDF, I think the issue is that you don't have any <joint> elements. Without a joint connecting two links, there is nothing for the robot_state_publisher to send on /tf. Try adding a link with only the name set, and a fixed joint connecting the two links

jarvisschultz gravatar image jarvisschultz  ( 2017-11-29 07:49:44 -0500 )edit

@jarvisschultz, I think it t could be also that, but I got the same error even after adding the joints. Ended up that the problem were the .dae files, that I created with rhino.I just had to export them to Blender as .3ds files and there export them as .dae files and everything worked

SteBisi gravatar image SteBisi  ( 2017-11-29 22:25:36 -0500 )edit

It would perhaps be good to see what the incompatibility is. Could you perhaps submit an issue to ros-visualization/rviz/issues with a minimal URDF and an example Collada file that shows this problem?

gvdhoorn gravatar image gvdhoorn  ( 2017-11-30 03:03:06 -0500 )edit

1 Answer

Sort by ยป oldest newest most voted
0

answered 2017-11-28 21:15:32 -0500

avcx gravatar image

Try adding inertial before the <visual>,, this way

  <inertial>
    <mass value="1.0" />
    <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0" />
  </inertial>

More accurate inertial can be from the CAD software itself. Also, often the mesh (*.dae or *.stl ) from CAD software will be in millimeters. So you might also need to scale the dimensions by 0.001 this way

<mesh filename="package://pkg_name/path/part.dae" scale="0.001 0.001 0.001"/>

edit flag offensive delete link more

Comments

Thank you for the answer, I tried to do what you said but I still ave the same problem

SteBisi gravatar image SteBisi  ( 2017-11-29 04:04:19 -0500 )edit

Question Tools

1 follower

Stats

Asked: 2017-11-28 12:12:42 -0500

Seen: 749 times

Last updated: Nov 29 '17