How to transfer a 3D model directly from ROS?

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Hi all. I have a ROS node creating a mesh out of the point cloud taken by robot. What I want to do is to simulate the robot behavior on the mesh.

I know there could be some problems with the dynamics computation if I updated the map during simulation. So I gave this up for now.

What I want to do is take one snapshot of that map, load it into Gazebo and do the simulations on that single map.

However, the only way I've found to get a model into Gazebo is to provide an XML (SDF, URDF) document. But that seems like a large overhead to me, since I already have the mesh as a visualization_msgs/Marker message in ROS (of type visualization_msgs::Marker::TRIANGLE_LIST).

Is there a way to import this Marker into Gazebo directly, without writing down the XML representation?

Thanks in advance for your ideas.