Override class naming rules for OpenAPI Code Generator

I'm trying to generate code from an OpenAPI specification that I got from another service provider. The specification uses schema name convention that results in very lengthy class names when generating the code. Is there a way to override the class name rules so I can add my own custom processing to trim the class names? I'm specifically looking for a way to do this using the Gradle codegen plugin. The code generation task has configuration for specifying prefix and/or suffix to the generated model classes, but there seems to be no way customise this further.