Subscribe Feed (RSS)Rippling 3D Animated Background
March 5th, 2009 by Rob Strobbe | Filed under Tutorials.Looping
Generally, a smooth looping background needs the last frame and the first frame to look similar or the same. Sometime ago, I learned a simple way of achieving that:
Select the noise texture event (and only that event) and split it somewhere. You’ll be left with two (not necessarily equal) events. Right-click the second one, drag it over the first one (staying on the same track), and let go of the right mouse button. From the context menu, choose Shuffle Events. You’ve just switched their places. (That was a bonus tip. No need to thank me.)
Play the loop again. Because the new first and last frames used to be adjacent, the loop is seamless, and the original problem frames are now next to each other where we can we can fix them. If we move the second event over to the left in order to overlap them, Vegas adds a crossfade between them and makes the change between them less abrupt.
Done, right? Not quite. I don’t like the crossfade. I think it’s too obvious and doesn’t fit in. I see that, and I know it’s not “part of” the animation. It’s simply there to mask where one half doesn’t match the other, and frankly doesn’t do it very well. But the crossfade does lead to the opportunity to add a transition, so I started experimenting with those, looking for something that would look more natural and become a part of the animation rather than interrupt it. I eventually decided that the Iris transition would do the trick. Here’s how:
Move the second half of the noise texture so that they overlap for as long as you want the transition to last. Consider the speed of movement — the more overlap, the longer the transition will take and the slower it will travel. Also, since you’re overlapping two events that originally added up to 10 seconds (assuming you didn’t change the default), your total noise texture component will now be less than 10 seconds. Be sure to change the solid color event to match.
Place the timeline cursor somewhere during the crossfade so you can see the result in the preview window while you adjust the transition settings — right in the middle would be best. Then go to the Transition window, select Iris from the list, find the Circle Out Upper Left White Border preset, and drag it onto the crossfade / overlapped area. Check out that preview window. A colored “3D” circle has been added with what appears to be the outgoing noise texture on the outside and the incoming noise texture on the inside.
To finish this off, the circle needs blend in more. The edge is too sharp because the border is entirely white – it’s all “peak” and no “slope.” By adjusting the Feather setting for the border, the edges of the circle gradually move from white to black (actually transparent, but it has the same result here), and, as a consequence, we introduce a “slope.” This allows it to look more like part of the other texture, keeping the transition from looking completely out of place.
Figure 4: Iris Transition
Tags: background, bump map, compositing, generated media, transitions
