I am importing a mesh and render it with this code:
<visual name="top_visual">
<transparency>0</transparency>
<pose>0 0 -0.0376785 0 0 1.5707</pose>
<geometry>
<mesh>
<uri>model://velodyne_hdl32/meshes/velodyne_top.dae</uri>
</mesh>
</geometry>
</visual>
It's there but invisible:
It's weird, because you can actually see it with view collisions on.