Rotate a cube off center

Tom Keane wrote on 4/7/2012, 3:44 PM

I've created a cube of pictures which is centered in the frame and can be rotated with the 3D parent track. Now I wish to move the cube horizontally to the left third of the screen and then rotate it there. When I use the "front" view of the parent track to move the cube along the x axis, it rotates somewhat so that the right side starts to come into view. Any idea how to simply move the whole cube horizontally so that it retains it's straight on orientation? Maybe move a "y axis" somewhere?

Thanks for any help.

Comments

Former user wrote on 4/7/2012, 4:01 PM

Can you use Track Motion?

Dave T2

Grazie wrote on 4/7/2012, 4:24 PM

Make the present Parent a Child of a further Parent, and use this Über-Parent to position.

G

Tom Keane wrote on 4/7/2012, 6:53 PM

Thanks for the response, Grazie. I added another parent and tried moving the cube at this level, but I get the same result...... can't move it straight horizontally (it begins to rotate as it move away from center). I made the new parent 3D track motion as well..... should I change some settings?

Thanks for the help.

TheHappyFriar wrote on 4/7/2012, 9:03 PM

Here's a 3D Parent Track Motion Tutorial: here

*insert Windows TaDa sound here*

jerald wrote on 4/7/2012, 9:21 PM

Hi, Tom,

If you want to see only the front of the cube while it's in the left side of the screen, then don't use displacement (i.e. don't use a value in the 'position' category). Rather, use rotation of the y axis of the top-most parent (i.e. change the value of y in either the 'orientation' or 'rotation' categories).

There are other ways to achieve the result, but the above will work most simply.

If I understand your explanation, the 'rotation' you're seeing as you move the constructed cube to screen left isn't actually rotation.

It is due to a change in the 'viewpoint.' In other words, if there is a large cubic building in an empty field and you start in a location to see it straight on like you describe seeing the cube in your video, and then you traverse to your right in the field (to 'move' the building to the left of your field of vision), eventually you'll begin seeing the side of the building.

Byron K wrote on 4/7/2012, 10:01 PM

Maybe you can import the .veg of the rotating cube on a separate track and use track motion to move it?

Tom Keane wrote on 4/8/2012, 9:49 AM

Jerald, you understand my situation perfectly. I am trying to change the "viewpoint" of the cube by shifting the cube left and still wanting to see it straight on to rotate it while in this position.

I tried your suggestion to change the rotation of the y axis of the top-most parent, but it doesn't seem to have an impact on the viewpoint. Would I need to "offset" the y axis?

I seem to be struggling with understanding a fundamental concept of how to simply shift the track view.

I appreciate all the help people are giving. I've spent days trying to figure this out on my own.

Arthur.S wrote on 4/8/2012, 1:50 PM

Could you simply use pan/crop to move it?

TheHappyFriar wrote on 4/8/2012, 3:04 PM

Oh, I think I see now.

I don't believe you can do this with the 3D track motion because it's 3D, it will always have perspective (if it didn't then it would be 2D). The best you could do is make a parent 2D track BUT then this will clip the child tracks below it. If you use a nested .veg it's easier but you still get clipped. You would need to increase the resolution of the project, move the 3D track back far enough so that it doesn't get clipped and nest that one.

Tom Keane wrote on 4/8/2012, 3:16 PM

Thanks Arthur. Unfortunately, I've got a 3 dimentional cube. A similar situation would be having 2 photos on two different tracks and using 3d track motion on each track, separating them on the z axis. Then with a parent track, you can rotate the photos together. John Rofrano has a tutorial on how to do this, and it all works fine around a center point.

I want to do the same basic thing, but with the photos shifted to the left to fit over a background. It doesn't work if I simply shift along the x axis because the viewpoint remains to the center creating a keystone effect to the photos. I've tried adding another parent track on the top thinking I could use it to shift the underlying parent/child tracks, but I can't figure how to manipulate the center point. Jerald said to move the y axis on the top parent, but I can't seem to get it to work. I'm probably just missing a basic concept here...... but it is frustrating.

Thanks for responding.

Rory Cooper wrote on 4/10/2012, 3:11 AM

I agree with Grazie for adding a complete 3D composite or big daddy track for your xy movement., because it allows you to control the cube xy scene movement independent of any xy movement on the cube.
Don’t use rotate xy for orientation rather use orientation xy this will sort your problem out, think of orientation as face camera xy Check the end for workflow image

FilmingPhotoGuy wrote on 4/12/2012, 12:33 AM

Hey Rory please email me the VEGGIE. I can never get my head around trying to create these 3D effects without getting my eyes crossed X-)

Rory Cooper wrote on 4/17/2012, 3:48 AM

I had a bit of fun using masks and 3d rotate

If you want the veg to play around with give ne a buzz roryc@tsogosun.com and I will send it.

It’s all masks so just replace images that’s it.

vtxrocketeer wrote on 4/17/2012, 7:22 AM

Hmph. Show-off. ;)

jerald wrote on 4/18/2012, 3:14 PM

Sorry for the delayed response, Tom. I've been away from the forum.

Short answer: Probably, yes. Try it and see.

Longer answer: Either yes, add another top level of parent (with all of the existing tracks 'childed' below it) and rotate THAT top level's Y-Orientation angle (assuming your project structure matches my understanding of it).

Longer answer may come later.

Bottom line is that the parent-motion functions generally correctly (in my experience).

However, the hard part (for me) of making it work is to be able to visualize what is being adjusted by each attribute of the parent motion for each level of parent motion. And, conversely, what attribute, on what parent motion level, to change, in order to accomplish a desired change in the resulting image.

I have not been successful in finding rigorous (i.e. in my opinion, appropriately detailed) documentation for parent motion functionality and attributes. I find that things work precisely well once I get the specific settings figured out, but so much of the necessary detail (such as the actual distance from viewer to the viewport) is left undocumented. I end up empirically (i.e. by playing around) determining things like this for each project.

If you'd like to see the result one of my early attempts at parent track motion, take a look at the following video:
2003.11.28...