Placing a keyframed camera into a null?

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  09 September 2012
Placing a keyframed camera into a null?

I have a long camera sequence that has been meticulously keyframed and approved. I now need to continue the camera move with an orbit and dip around a central object.

The most obvious way to do this sort of thing is to place a null at the center of the orbit and then keyframe the rotation of the null---which is how I would have rigged my camera had I realized this move was necessary when i had begun.

Placing the camera in a pre-positioned null offsets the cameras position in space...which of course I do not want.

I could create a new camera constrained to the original camera, and place THAT cam in a null...but that presents issues as well.

So my question is, what is the best way to do this now that the camera is already keyframed?

I'm sure there is an easy answer here, and sure I've solved it before, but cannot figure it out at this moment.

Thanks in advance!
  09 September 2012
Could you cut (seamlessly) to a new camera at that point (with matching parameters), which is parented to a null?
  09 September 2012
steadyGLIDE it from the keyframed to the orbited

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  09 September 2012
@Mike Abbott Yes, I could do that, and holding that one in my back pocket--however would prefer one continuous cam move. This will be a stereo (not to mention full dome) shot and Im working with an offsite team and want to keep everything as simple as possible.

@Lennart--thought about that one too, however (as in my reply to Mike) would prefer keeping this a native solution if possible. Plugins will make matters more complicated due to working with other animators and renderfarms--plus the stereo/full dome issue. It is however a possibility if nothing else works.

Thanks guys!

Last edited by JoelDubin : 09 September 2012 at 02:34 PM.
  09 September 2012
If your camera is a child of the world then make a null at world origin and make the camera a child of it. No animation should change. Then if u wanna orbit world animate that null. If u wanna orbit from a different origin then just put that null as a child of the orbit object. Should preserve the animation unless im misunderstanding.
"We do not - not wag our genitals at one another to make a point!"
  09 September 2012
Ok, here's a shot:

1. Run your camera to the end of it's animation path - where you want to transition to the orbit.
2. Create a null - match it's world co-ordinates to the camera co-ords.
3. Run the camera back to the start of its animation path
4. Now place the camera as a child of the null.
5. Set the null co-ords to world zero.

  09 September 2012
Thanks Bret and Mike

Going to absorb this info and give it a try...
  09 September 2012
Thinking about this again - I'm sure Brett's right. If your camera animating in world space adding a null shouldn't be an issue.

My guess is:

When you added the null, did you 'Alt-G' to group the camera - if so your null would be located at the camera position - which would offset the path.
You need the add the null manually - so it's at world zero, then drop the camera into it.

  09 September 2012
Yup, what Bret said. One null at world origin which will preserve the existing animation but allow you to reposition it. Make the camera a child of that first null. Then create a 2nd null where you want the new axis of rotation to be, make the first null a child of that 2nd null and now you can move/animate etc the 2nd null without affecting the original animation at all.

Sounds a little abstract but it's easy in practice once you've done it a couple of times.

Mike is right too - don't Alt+G to group the camera as that will put the null at it's current location which will offset it when the animation updates, create the nulls manually instead.


Last edited by Horganovski : 09 September 2012 at 03:53 PM.
  09 September 2012
Thanks again guys.

The camera was keyframed as a "child to the world" (so to speak), as it was not parented to any object but keyframed in "free space"

The location the camera will orbit around, is NOT at 0,0,0, world space (its at a location elsewhere in the scene).

I am creating a null in worldspace (not grouping) and then transferring its coordinates to the point in space I need it to be.

But then when I drag the camera under the null in the OM, the camera, and all animation then offsets relative to that new point in space.

I still havent gone through your comments carefully enough yet, but will try again...
  09 September 2012

(slaps head)

And yes--I've been down this same road before and solved it through this same process.
Momentary lapse of memory. I'm getting old.

Thanks again all!
  09 September 2012
Put your new null where you need it and use Character>Commands>set parent.
  09 September 2012
Originally Posted by Shane W: Put your new null where you need it and use Character>Commands>set parent.

Thanks Shane--good to know
  09 September 2012
As a matter of course I start a new scene with a new Null, name it CAMS or VIEWS and drop new cameras into it. I will also put in a Stage object for camera switching if I need to test views for multiple stills or passes. Before getting to final shots I may have quite a lot of test cameras, and all of them fold neatly under that Null, which is at 0,0,0
Ernest Burden III
Acme Digital
  09 September 2012
There are several solutions, you cold also use a stage object to switch to a second camera, or create your null where you need it at frame zero, place the camera as a child and the zero the offsets using the animation tool (document mode) in the coordinates manager, then there's using retargeting and things like the constraint tag to add a virtual parent constraint to the camera etc
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