Got one that I can't seem to get to the bottom of.
I have an object traveling along a spine via the Spline Wrap deformer that I am having a hell of a time attaching an external compositing tag to a certain point on the object.
Let me be more clear. The reason i'm using the Spline Wrap, is that my object is a Passenger train. rather than go through the trouble of rigging it for the short shot, i just set it up to travel along the spline with spline wrap set to 'keep length' and voila, easy train rig.
The train rig is made up of several polygonal objects (an engine, and three cars plus their wheels) that are all grouped together and move along my spline just fine.
On one of the passenger cars, I have to spots for 'signs' on the side of the car that i'd like to composite video on in post in AE. When I apply a compositing tag and activate the object buffers, i get those in the render just fine. The problem comes when I want to emply External compositing tags to send nulls to AE. The tags create nulls in the original position of the train, not the position of the train as it moves down the spline.
Here's what I've tried.
Aside from just applying the external comp tag, I've also tried a little xpresso from some tips i picked up through some other posts. Mainly I've connected nulls to point nodes that are attached to the global position of the signs i want the nulls to attach to. No dice.
This would be easy i wanted a null at the front of the train, I could just use an align to spline tag tweaked with an xpresso tag I found over at base80.com and i'd be in business, but since this is in the middle of the train, i'm stuck.
Any help would be HUGELY appreciated as I'm at the end of my resources trying to track down a fix for this and I REAAAAAALLY don't want to hand track in AE:)
here is a link to a scaled down version of my project:
Happy Thanksgiving to all of you State Side and thanks in advanace for all your advice!