For Quartz Composer effects to appear in the CamTwist effects list, certain conditions have to be met within the composition itself. The page Adding effects with Quartz Composer
may be helpful to you in that regard. Additionally, it's necessary to either Refresh Effects List
via the File menu or to quit and restart CamTwist before the newly added effects will appear in the effects list.
Be advised that I'm merely an enthusiastic CamTwist user with some rudimentary Quartz Composer experience. The developer may have additional advice about adding effects or comments about the 10.5 folder. As mentioned in this posting
, I'm available for conferencing via IM, Skype or private messaging in this forum for more detailed discussion regarding the basic construction of Quartz effects for CamTwist.