spawning spheres in gazebo as simulated point cloud
So I'm working on spawning spheres in gazebo to simulate point clouds for probabilities. I have been able to spawn objects with the command line,
rosrun gazebo spawn_model -file /opt/ros/electric/stacks/simulator_gazebo/gazebo_worlds/objects/simple_box.urdf -urdf -x 1.18 -y .91 -z 1.549 -model box1
but it seems when spawning objects this way you can't make them static, or resize the objects.
Is there a way to spawn objects with the ability to make them unaffected by gravity and resize-able?