[Ryan Hill]

That would depend on what kind of movement you’re trying to achieve. Normally, you won’t use a null at exactly the same point as either the camera or the point of interest or it would be redundant. More likely, you’ll set the anchor point somewhere you want to rotate around, though there’s a lot of other things you can do with that.

You might pick-whip the camera’s position to the position of the null, which isn’t redundant, because the camera would still use its own rotation values. Or you can set the null as the parent of the camera, and then it also rotate with the null.

[Ryan Hill]

That would depend on what kind of movement you’re trying to achieve. Normally, you won’t use a null at exactly the same point as either the camera or the point of interest or it would be redundant. More likely, you’ll set the anchor point somewhere you want to rotate around, though there’s a lot of other things you can do with that.

You might pick-whip the camera’s position to the position of the null, which isn’t redundant, because the camera would still use its own rotation values. Or you can set the null as the parent of the camera, and then it also rotate with the null.

[Ryan Hill]

So if the distance doesn’t much matter, then you can assume the hypoteneuse is 1, making the math a little simpler.

Something like:

[position[0]+Math.sin(rotationY),
position[1]+Math.sin(rotationZ),
position[2]+Math.sin(rotationX)]

I might have X Y and Z backwards, but it makes sense to me. And you’ll want to pick-whip to get the real attributes of your camera.

Also, you might be able to avoid expressions by parenting a null layer to the camera, with the anchor right on the camera, and the position right at where you want the point of interest. But I can’t test any of this right now, because I’m not at a computer that has AE.

[Ryan Hill]

So if the distance doesn’t much matter, then you can assume the hypoteneuse is 1, making the math a little simpler.

Something like:

[position[0]+Math.sin(rotationY),
position[1]+Math.sin(rotationZ),
position[2]+Math.sin(rotationX)]

I might have X Y and Z backwards, but it makes sense to me. And you’ll want to pick-whip to get the real attributes of your camera.

Also, you might be able to avoid expressions by parenting a null layer to the camera, with the anchor right on the camera, and the position right at where you want the point of interest. But I can’t test any of this right now, because I’m not at a computer that has AE.

[Ryan Hill]

You know the X, Y, and Z location of the camera, and the angles it’s pointing. You want to calculate the location of the point of interest.

Just to get one thing out of the way; there is no one single answer as to where the point of interest will be. It can be anywhere along a line pointing away from the camera. So, you’re going to have to assign a distance arbitrarily, to get a single point.

What exactly do you plan to do with this point once you have it?

[Ryan Hill]

You know the X, Y, and Z location of the camera, and the angles it’s pointing. You want to calculate the location of the point of interest.

Just to get one thing out of the way; there is no one single answer as to where the point of interest will be. It can be anywhere along a line pointing away from the camera. So, you’re going to have to assign a distance arbitrarily, to get a single point.

What exactly do you plan to do with this point once you have it?

[Ryan Hill]

https://forums.creativecow.net/cgi-bin/dev_read_post.cgi?forumid=2&postid=870250

[Ryan Hill]

Trigonometry. I believe there are sin cos and tan functions available.

This covers some related subject matters:
https://www.creativecow.net/show.php?page=/articles/ebberts_dan/particle_gen/index.html

[Ryan Hill]

Trigonometry. I believe there are sin cos and tan functions available.

This covers some related subject matters:
https://www.creativecow.net/show.php?page=/articles/ebberts_dan/particle_gen/index.html

[Ryan Hill]

Shoot green-screen, or wear black and shoot against a white background, and then play around with the levels.