I have a pretty simple radial gradient applied to two circles to simulate a pulse effect. Is it possible to replicate this same effect but with a hexagon for the shapes? It would be best to know how this is done in Illustrator.

You can probably get it done, not with gradients but with blends. Try making a big hexagon with the green color, a smaller one with the background color and blending. Duplicate and scale for the center.

This is my own 1-minute attempt:

• imho, this should be the accepted answer. It's way cleaner and easier than bemdesign's solution. – Vincent Jan 21 '16 at 11:53
• Great solution! – bemdesign Jan 21 '16 at 12:15

So I originally thought this isn't possible but then geometry for the win! A hexagon can be created from 6 triangles.

1. Create a triangle shape and give it a linear gradient
2. Copy the triangle and past in front of the original triangle.
3. Rotate the new triangle by 60 degrees.
4. Position new triangle.
5. Repeat step 2 but now rotate the new triangle by -60 degrees.
6. Align the triangles to make the top of the hexagon.
7. Copy the 3 aligned triangles and past in front.
8. Rotate these new triangles (as a group) 180 degrees.
9. Align the new triangles to form the bottom of the hexagon.
10. There you go! A hexagon with a similar-ish radial gradient as to your original circles (the hexagon's gradient will have a bit of a "starburst ray" effect along the edges where the triangles meet at the edges).
• Thanks @bemdesign! This works just like you suggested, but with what I'm imagining as my goal, it won't be possible with this way or any other methods. Thanks again! – Eugene Ross Jan 21 '16 at 4:54