# Revision history [back]

I see you have a lot of fixed joints on your URDF. When converted to SDF, links connected by fixed joints are lumped together into links for performance, and as a consequence, the link names change.

One thing you could try would be to use the preserveFixedJoint on your URDF, so that the fixed joints are persisted, and link names and poses don't change, for example:

<joint name="camera_joint" type="fixed">
...
</joint>
<gazebo reference='camera_joint'>"
<preserveFixedJoint>true</preserveFixedJoint>"
</gazebo>"