View Full Version : Trailer: making it smoother?

06-07-2012, 11:32 PM
I've been doing some tests with DStorm's Trailer plugin, and sometimes it seems like the displacement is less smooth than ideal, because there's just not enough frames in the motion path to make a smooth curve.

Would it be possible/practical to make the animation frame rate twice its normal rate, to insert more frames for the plugin to distort the geometry over, but then only render every other frame, to get the same number of frames in the final animation?

06-08-2012, 03:09 AM
I ran in to this problem to. It makes it useless in most cases. It would be nice if the plugin maker enabled sub-frame calculations.
Sometimes the curve get smoother when the object isn't scaled in layout.

06-08-2012, 04:39 AM
If youre on a PC you could always try shift spline transform. It allows an object to be deformed by a spline but will also animate along the spline.

06-08-2012, 08:06 AM
Larry, I'm trying to get by with purely 64bit plugins.

The frustrating thing is Trailer is 98% there, but that last 2% is the killer. I also tried futzing with the Smoothing factor to no avail.

06-08-2012, 09:27 AM
could you share the scene, i'd like to have a look...
(or post image)

06-08-2012, 09:59 AM
could you share the scene, i'd like to have a look...
(or post image)

Here ya go.

Render the whole thing out (won't take long): at certain frames, the curve is just not smooth, it creates some slight kinking in the tube object. I think I've got enough divisions in the object that this shouldn't occur: my theory is that the object is fine, there's just not "enough frames" in the path to create a smooth displacement.

Naturally, I'd prefer a perfectly smooth displacement.

I'll be interested in hearing what you come up with.

(Looking at this, it seems that the Motion Object twists around more than it should. I'm not sure how that happened, but perhaps this untoward rotation is contributing to the problem. Or not.)

06-08-2012, 03:38 PM
Just a suggestion...
If you need more frames to get a more detailed motion path. Try saving the motion and converting it to a spline in modeler. Rail extrude a single point poly along the spline to get a string of 2pt polys. Select the points and convert it back into a spline. I believe that each point or knot on the spline represents 5 frames in layout after you reexport the spline back out as a motion path in layout. If this fixes the kinking problem, try mdscanning the rope object and then control the playback speed with something like dponts mdd playback node.

06-08-2012, 05:29 PM
Larry, I'll look into that, but:
Is the number of frames per knot always going to be 5, independent of the frame rate?

(Somewhere in the back of my tired brain is a group of cells yelling "Stupid question! Don't hit SEND!!!" Screw those guys.)

06-08-2012, 06:18 PM
If you have 100 knots it will be 500 frames. :)
But this should give you enough resolution in the curve to hopefully maintain
the shape. Once you mdscan it then you can use that node to control the playback speed
to what you actually need :)

06-09-2012, 12:37 PM
While I try to implement Larry's suggestion, a question about whether I'm barking up the wrong tree or not:

When you've got something as finely divided as this object, and triangulated (all 3gons), should it be possible to solve any smoothing effects using just Surface attributes?

(I'm guessing "no", because the edge/profile of the object has the wobble too, not just the rendered bits.)
ADD ATTACHMENT: here's the effect I'm referring to, and trying to avoid (see image). :cursin:

06-10-2012, 12:30 AM
I took Larry's suggestion above (and very interesting it was), resulting in a motion path of ~1420 frames. Lots of keyframes and frames for Trailer to work its magic.

Unfortunately (see attached) the crinkling/crimping effect is still visible. Attached is a render of frame 325 with the problems indicated (although they are glaringly obvious).

Now that I've had time to reminisce, I remember that a previous use of Trailer on a 2 dimensional ribbon had similar problems, although I think I was able to subdivide it into submission (although Trailer does not work with sub-d's). That is, I metaformed it mercilessly and probably mucked with the smoothing factor too.

I attach the scene in case anyone wants to explore on their own.