Tuesday, December 6, 2011

Moving holds


Usually, holding a CG object for several frames without movement is considered to be a NO-NO. There MUST be some movement, even if very small. Here's one easy way to do that.
Let's bring the cube and make some simple animation with it.

Red outline is previous position of the cube. Yellow and blue arrows are directions of the movement. Brown ovals and rectangles are the holds.

Playblast

Let's curve those holds now, so the cube doesn't feel like sticking.
We'll do it manually this time.

Red dotted lines are the previous flat positions of the curve. Yellow arrows show directions of the knots shift. Yellow rectangles in timeline are the holds (moving holds they are now).
Playblast 

Done deal.

Now let's consider more complex situation. We'll add rotations to the movement.

Playblast 

If we will decide to work manually, we'll have to work with every curve. The big problem here is proportion. The bigger movement "1" must be adjusted more and the smallest "2" -  less. But how do we know how much?
There is a very convenient way to do it easy, at least for the bulk part, and forget about the problem, at least for a while - using Middle Mouse Drag and Drop function in the Timeline.

We need to make red curve to look like yellow dotted line.

So we need to lower the knot on frame 18 to be at the level of blue knot (blue arrow points at it).
Move the mouse in the Timeline until red crossline intersects the curve approximately where blue dot is. In our case it will be frame 17 (in blue circle)

Press Middle Mouse Button (MMB), hold it down and move cursor from frame 17 to frame 18. Release MMB and ...


hit 'S' on the keyboard.

There you go.

But notice that  not only red curve moved, but also the blue.
And if we hit 'A' in Graph Editor window, it will maximize the view and we'll see that Blue curve(TrZ) almost exactly follows Red one (RotX). I think it means that it has the same proportion of curvature as the Rot X.


It happens to all curves.
Green arrows show direction of the MMB drag and drop.


Playblast

MMB is one of the most important tools for animation. Use it.

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