Creating a solar system

[Thehardmenpath]

Hi. One usual way to make orbits properly is to create a circular mask (better on a solid that fits the comp area) with the circular mask tool. Create it, distort it if you want, select the path and paste it into the position of a (planet) layer. The path will be exactly copied. Make this with all the planets, turn them into 3d layers, and choose what you say, the orient towards camera option. Now create a 3d camera and place it where you want.

For changing the cycle speeds just drag one of the square keyframes. For looping the rotation, create an expression on the position value:

LoopOut(type = “cycle”)

You can see how this very expression is implemented in a tutorial by Aaron Rabinowitz: How to create a flock of birds, part 1.

[Steve Roberts]

Another option is to create a null for the center of the solar system and parent a planet to it. You then rotate the null, and the planet orbits it. Repeat for each planet, tilting the null slightly if you wish. Name the nulls appropriately and use coloured layers to keep everything straight.

[Ryan Hill]

Depending on how precise you want to be with the orbits being elliptical vs. circular.

If you want to be really precise, employ Kepler’s laws as an expression
https://en.wikipedia.org/wiki/Kepler's_laws_of_planetary_motion#Solution_for_the_motion_as_a_function_of_time

[Ryan Hill]

Really the only benefit of using that formula over an elliptical path or a scaled rotating null, is that the speed of the planet varies over the course of one orbit.

[Betty Boop2]

Thank you Steve that seems to work quite well. One more question….when the planets orbit around (right to left) they are just fine BUT how get them to apear to go behind the sun and not in front of it. Know what I mean?

Jay Thompson
Thompson Visual Design & Storytelling
7 Marjean Ct.
Kirkwood, MO 63122

[Rob Montague]

This might help:
https://www.creativecow.net/show.php?page=/articles/laronde_dave/planets/index.html

[Steve Roberts]

Well, place the sun where the null is … in the center of the solar system, and make sure all layers have their 3D box checked. Also make sure you have no 2D layers between the 3D layers in the layer stack.

You might want to open up new 3D views to get a different perspective as you work.

And make sure you actually create a camera. Don’t use AE’s default sort-of camera, or you may get messed up down the line.

[Betty Boop2]

Thanks everybody. Big help!

Jay Thompson
Thompson Visual Design & Storytelling
7 Marjean Ct.
Kirkwood, MO 63122