How to add/delete a object mutliple times from a single model file using a plug-in

edit

Assuming you're using a WorldPlugin, you can use the World::InsertModelSDF or World::InsertModelString API's (see example code from updated tutorial). You can specify the model name as an attribute in the passed SDF object or SDF string. I'm updating the example to show how to do this (pull request #957).

I don't think it's currently possible to specify a custom model name when spawning via a filename with a factory message, though it can be done when passing custom sdf strings (see numerous spawning functions in the ServerFixture class).

I've been doing this by keeping track of whether a model type exists within the world, and using the clonemodelname field of the factory message to spawn sequential models. With this method, each new model takes the previous with "_clone" appended to its name. Unfortunately, the functions within physics::World needed modify the model name before spawning are private, so I don't think there's a better way right now.

You can delete models using the "entity_delete" field on the "~/request" topic. Just fill in the model name.