STL exporter should be upgraded.

[simjeh]

• Option 1. Normal version. Current output method with a single mesh file.

• Option 2. Detail version. Separate meshes with each component, Export meshes by every component, and put it XML as visual attributes.
  EX)
  

  fusion360descriptor/FullBody_description/urdf/FullBody.urdf

  Lines 1 to 44 in 9e69bd0

  	<?xml version="1.0" ?>
  	<robot name="FullBody">
  	<material name="silver">
  	<color rgba="0.700 0.700 0.700 1.000"/>
  	</material>
  	<material name="red">
  	<color rgba="1.0 0.0 0.0 1.000"/>
  	</material>
  	<link name="L_Pelvisv12_1">
  	<inertial>
  	<origin xyz="-0.00016823298939081687 0.07887151231400673 -0.22549351371810145" rpy="0 0 0"/>
  	<mass value="12.545724119282553"/>
  	<inertia ixx="0.05811" iyy="0.10775" izz="0.13684" ixy="0.000156" iyz="0.005835" ixz="-4.7e-05"/>
  	</inertial>
  	<visual>
  	<origin xyz="0 0 0" rpy="0 0 0"/>
  	<geometry>
  	<mesh filename="package://meshes/L_Pelvisv12_1.stl" scale="0.001 0.001 0.001"/>
  	</geometry>
  	<material name="silver"/>
  	</visual>
  	<visual>
  	<origin xyz="0 0 0" rpy="0 0 0"/>
  	<geometry>
  	<mesh filename="package://meshes/L_Pelvisv12_1.stl" scale="0.001 0.001 0.001"/>
  	</geometry>
  	<material name="silver"/>
  	</visual>
  	<visual>
  	<origin xyz="0 0 0.01" rpy="0 0 0"/>
  	<geometry>
  	<mesh filename="package://meshes/L_Pelvisv12_1.stl" scale="0.001 0.001 0.001"/>
  	</geometry>
  	<material name="red"/>
  	</visual>
  	<collision>
  	<origin xyz="0 0 0" rpy="0 0 0"/>
  	<geometry>
  	<mesh filename="package://meshes/L_Pelvisv12_1.stl" scale="0.001 0.001 0.001"/>
  	</geometry>
  	</collision>
  	</link>

So multiple visual and collision attributes are ok. And we should not forget to put color info like this way at just below of robot name.

• Option 3. Simplified version. Mathew did this job on another project. So we need to merge this after exporting STL files with normal version and make convex hull STL.

Maybe option 4. Simplified with a detailed version. If we separate mesh with components then it could be better to build convex hulls.
I am not sure if this makes the simulator slower or not. So this might need some test.