Align to spline camera and object animation jittery issue

[Brian Jones]

the splines have a different number of points so have a different number of total points with Uniform (check the Help on Intermediate Points). And the shapes of the two F-Curves for the position parameters of the Align tags don’t have the same number of points and are a mix of Linear and curved… those inequalities are causing the jumpiness I think.
It might be easier to make the camera be a child of the bus (and ditch the second spline altogether) and animate it where you need so you get the same result, only better.

[Jesse Stormer]

I can’t have the camera be a child because I have it ‘Leave’ the bus all together at one point, it isn’t always with it. I see your point about having inconsistent numbers of points on each spline. But, I thought that was the point of the spline? That regardless of what location you are at on the spline, it is based on algorithm? That’s supposed to be the benefit of using a spline. Thanks for the help! I’ll try just adding pointless points just so that they might calculate more similarly.

[Brian Jones]

you still can’t get around the different Align to Spline tag’s Position parameters, with one having two keyframes and being linear and the other having 4 (not evenly spaced) and being partly linear and partly curved.
If the camera leaves the bus it has to stay inside the Null (which followed the spline) and you end up animating the camera in the coordinate system of the Null. You could still do the same thing with the camera as a child of the bus you are just inside the bus’s coordinate system.
If your camera is going a short distance no problem either way but if you are going to be animating the camera for a long time/distance I would jump to a new camera when the ‘follow the bus’ shot is done. Either line it up exactly if you are making a cut-less shot, or do a cut at that point or do a Camera Morph to the new camera

[Adam Trachtenberg]

I would change the spline type of the path splines from uniform to subdivided and then redo the animation of the chase camera tag.

[Jesse Stormer]

Because the bus jumps forwards and backwards, it leads me to believe that locations along the spline aren’t being calculated to a small enough decimal. Like it’s being rounded to the nearest tenth or hundredth? I honestly am feeling like this is a software issue, I can accomplish this in Max.

[Jesse Stormer]

Then there’s the fact that when I bake everything that’s animated on the splines, and try to reduce keys — it looks like this:

[Adam Trachtenberg]

I think the problem with the camera has to do with the fact that the splines have different point counts. I was able to fix it by substituting in mosplines that have the same point counts.

As far as key reduction goes, yeah, Cinema is pretty lame in that area. Might be worth investing a little in the Nitrobake plugin which in this case produces a good result with 1/4 of the keys.

File: 6501_camerafixedamt.c4d.zip

[Jesse Stormer]

Wow, Adam. Thank you so much, I’m very impressed that you were able to figure this out! I’m still not 100% on why this didn’t work with a different type of spline. So, what was your process for converting the spline to MoSpline? It’s just as simple as telling the MoSpline to reference my original splines? Your solution is curiously/frustratingly easy… considering how long I spent on this dilemma.

[Adam Trachtenberg]

It was a bit of a head scratcher but I was sure it had to do with the spline interpolation.

Mospline is often good for those sorts of problems. It is as easy as setting the mospline mode to spline, dragging your spline into the reference box, setting the type to even, and then specifying how many segments you want.