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I would like to build a simple robot model in urdf with just visualization and display it in rviz. I just have one tf frame for the body (it is a quad rotor) so how can I use the same frame for more than on geometry element?
Or is it possible to take a 3D model and just use that?
Short answer is that you currently can't do exactly what you're saying.
The easiest way to get around it is to create a second link with an appropriate offset, connected with a fixed joint.
This does create an extra frame which will need to be published. This is most often handled with robot_state_publisher.
I suppose I will get one extra frame per geomtry I want to have. I was afraid that would give possible delays but maybe it will work. I will test it. SO if I used tix joints I can use robot_state_publisher. I assume I could also just have no joints and just publish the frames from my program.
Following is the full code of the first version of the urdf of the robots I'm working on.
<?xml version="1.0"?>
<robot name="Saetta">
<link name="base_link">
</link>
<link name="body">
<visual>
<geometry>
<box size="0.195 0.145 0.055"/>
</geometry>
<origin rpy="0 0 0" xyz="0 0 0.032"/>
<material name="grey">
<color rgba="0.5 0.5 0.5 1"/>
</material>
</visual>
</link>
<link name="cover">
<visual>
<geometry>
<box size="0.195 0.145 0.02"/>
</geometry>
<origin rpy="0 0 0" xyz="0 0 0.069"/>
<material name="dark_transparent_grey">
<color rgba="0.2 0.2 0.2 0.5"/>
</material>
</visual>
</link>
<link name="right_wheel">
<visual>
<geometry>
<cylinder radius="0.032" length=".007"/>
</geometry>
<origin rpy="0 1.57075 1.57075" xyz="0 -0.085 0.032"/>
<material name="wheel_metal">
<color rgba="0.7 0.6 0.6 1"/>
</material>
</visual>
</link>
<link name="left_wheel">
<visual>
<geometry>
<cylinder radius="0.032" length=".007"/>
</geometry>
<origin rpy="0 1.57075 1.57075" xyz="0 0.085 0.032"/>
<material name="wheel_metal"/>
</visual>
</link>
<link name="castor_support">
<visual>
<geometry>
<box size="0.05 0.027 0.02"/>
</geometry>
<origin rpy="0 0 0" xyz="0.1225 0 0.02"/>
<material name="black">
<color rgba="0 0 0 1"/>
</material>
</visual>
</link>
<link name="castor_wheel">
<visual>
<geometry>
<sphere radius="0.01"/>
</geometry>
<origin rpy="0 0 0" xyz="0.1225 0 0.01"/>
<material name="black"/>
</visual>
</link>
<link name="sensor_front_left">
<visual>
<geometry>
<box size="0.03 0.022 0.01"/>
</geometry>
<origin rpy="0 1.57075 1.30915" xyz="0.082 -0.08 0.032"/>
<material name="black"/>
</visual>
</link>
<link name="sensor_front">
<visual>
<geometry>
<box size="0.03 0.022 0.01"/>
</geometry>
<origin rpy="0 1.57075 0" xyz="0.11 0 0.05"/>
<material name="black"/>
</visual>
</link>
<link name="sensor_front_right">
<visual>
<geometry>
<box size="0.03 0.022 0.01"/>
</geometry>
<origin rpy="0 1.57075 1.83235" xyz="0.082 0.08 0.032"/>
<material name="black"/>
</visual>
</link>
<link name="sensor_rear_right">
<visual>
<geometry>
<box size="0.03 0.022 0.01"/>
</geometry>
<origin rpy="0 1.57075 0" xyz="-0.082 -0.08 0.032"/>
<material name="black"/>
</visual>
</link>
<link name="sensor_rear_left">
<visual>
<geometry>
<box size="0.03 0.022 0.01"/>
</geometry>
<origin rpy="0 1.57075 0" xyz="-0.082 0.08 0.032"/>
<material name="black"/>
</visual>
</link>
<joint name="body_to_cover" type="fixed">
<parent link="body"/>
<child link="cover"/>
<origin xyz="0 0 0"/>
</joint>
<joint name="body_to_right_wheel" type="fixed">
<parent link="body"/>
<child link="right_wheel"/>
<origin xyz="0 0 0"/>
</joint>
<joint name="body_to_left_wheel" type="fixed">
<parent link="body"/>
<child link="left_wheel"/>
<origin xyz="0 0 0"/>
</joint>
<joint name="body_to_castor_support" type="fixed">
<parent link="body"/>
<child link="castor_support"/>
<origin xyz=" 0 0 0"/>
</joint>
<joint name="castor_support_to_castor_wheel" type="fixed">
<parent link="castor_support"/>
<child link="castor_wheel"/>
<origin xyz=" 0 0 0"/>
</joint>
<joint name="base_to_body" type="fixed">
<parent link="base_link"/>
<child link="body"/>
<origin ...Asked: 2013-02-21 07:46:45 -0600
Seen: 467 times
Last updated: Feb 21 '13
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