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3D Camera, 3D Null, CC Sphere
Hey guys.
I may be missing something obvious, but I haven’t been able to get this to work.
I have a null object that is at [0,0,0] and is rotating. I have a Camera that is moving through space and rotating around the the null. What I need to do is “attach” a CC Sphere layer to this null. That is, the sphere needs to scale and rotate to match the camera’s movement combined with the null’s rotation.
I know about the usual tricks (toComp, lookAt) but I can’t think of a way to make these work. Having the sphere look at the camera and adding the rotation of the null to that value doesn’t seem to work correctly.
Thanks in advance.
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1 Reply
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Unfortunately, CC SPhere appears to be using a different order for axis-rotation, than the main After Effects 3D world.
Also it’s not clear through what virtual lens we’re looking at the CC SPhereIf you turn over X 30°, then Y 15°, then Z 8°
you get a different result than Y 15°, Z 8°, X 30°That’s why just piping in the values from After Effects through a pickwhip expression doesn’t work.
It’s the same with XYZ-rotation and Orientation, they seem the same for simple rotations, but set some keyframes and pretty soon it doesn’t add up anymore.
This apparantly has to do with 4dimensional coördinates called quaternions…
And that is some pretty hard math to crack.I think Dan has had some succes calculating the virtual angle of the CCSphere with just 2 axis of rotation in the past, or using the LookAt in combination with “orient to camera”
But I’ve found that I would always come up with angles where this still didn’t work.
Give it a go, it might work for you.It’s described in detail in this tutorial.
https://www.videocopilot.net/tutorial/the_blue_planet_in_3d/
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