You could create a Repeater field for your Projects containing the following:
- A post type Relationship, that allows only a single post, limited to
Creator
- A taxonomy Relationship, limited to your role taxonomy (Director, Animator etc.)
When editing the Project you can then create a new Repeater item for each Creator and assign it roles. The downside is that in the Creator templates you would have to query Projects in order to check what the Creator at hand is involved with, which, depending on the scale of your website, could be rather expensive.
