How to change default Ignition renderer?

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I am trying to test out Ignition Fortress (as source install for what its worth), but my machine doesn't support OpenGL >3.3 and thus I can't get the Ogre2 render engine to run without Ignition immediately crashing. I can work around this issue by selecting the Ogre1 engine when I start ignition (ign gazebo shapes.sdf --render-engine ogre) but its a bit tedious to manually specify each time, and a pain to edit the launch files for demos that I want to try out (e.g. ign_ros2_control).

What is the best way to change the default Render Engine?

Thanks!