Black screen and error reporting when loading custom models for gazebo with roslaunch

Today, I made one by myself dae Type of model file , Want to import gazebo, according to gazebo .world Import in file dae The problem with the model The article has been operated , Write as follows .world file

<?xml version="1.0"?>
<sdf version="1.4">
  <world name="default">
    <include>
      <uri>model://sun</uri>
    </include>
    <include>
      <uri>model://ground_plane</uri>
    </include>
    <model name="SparsePillars">
      <pose>0 0 0 0 0 0</pose>
      <static>true</static>
      <link name="up">
        <visual name="visual">
          <geometry>
            <mesh><uri>file://SparsePillars.dae</uri></mesh>
          </geometry>
        </visual>
      </link>
    </model>
  </world>
</sdf>

Use this .world file , Use it directly gazebo worldname.world when gazebo Can start normally , But use roslaunch load world When gazebo Will always be stuck in the black screen of the loading interface , And report the following error

[Err] [ModelDatabase.cc:414] Unable to download model[model://SparsePillars.dae]
[Err] [SystemPaths.cc:412] File or path does not exist[""]
[Err] [Visual.cc:2824] No mesh specified

Check information 、 After looking for problems for a day , Finally in the gazebo Found in the Q & A area of the official website A post , The final solution is .world file uri Change the address to absolute address , And in front of the absolute address The backslash / Three are needed ！ Specifically world The documents are as follows

<sdf version="1.6">
  <world name="default">
    <include>
      <uri>model://sun</uri>
    </include>
    <include>
      <uri>model://ground_plane</uri>
    </include>
    <model name="SparsePillars">
      <pose>0 0 0.0  0 0 0</pose>
      <static>true</static>
      <link name="up">
        <visual name="visual">
          <geometry>
            <mesh><uri>file:///home/muguang629/Simulator/SparsePillars.dae</uri></mesh>
          </geometry>
        </visual>
      </link>
    </model>
  </world>
</sdf>

Use this world file ,roslaunch It will start normally