Yes, "always consult the manual page" ( the hit single from the new CD by my
band, Grazing Zebra).
I struggled with this too until a light finally went on. It is related to
the question, "How far is it to Chicago in miles per hour?" Here is my
(more-or-less) plain language description.
When a jitter matrix passes through jit.slide, it "slides" from the previous
frame by an interpolation method that you see in the equation on the help
page. The time it takes to slide is determined by the slide up/down values.
These values are not in fact time but rate. The further the distance, the
longer the time.
(Jitter gurus correct this next part as necessary) If you have a pixel with
a value 0.0 in the starting frame and 1.0 in the ending frame it will take
longer to interpolate than te pixel pair 0.1-0.2. Different frames in the
same movie with take different times depending on the values of the pixels.
Frames that are similar arrive more quickly.
It's akin to reverberation. If you set a reverb time of 2.0 seconds and
play a loud sound it will take longer to decay than a soft sound because the
process involves feedback.
The first starts at 100% and decays by a factor of 0.9. At the 10th sample
it reaches approximately 1/3 of its original value. With same decay factor,
the second starts at 50% and reaches 1/3 around the 5th sample.
Gary Lee Nelson
> Yeah. I read the help file and the reference manual entry, but I
> have to confess, didn't quite understand them. Sorry to be really
> thick, but i guess i don't really understand the formula:
> y(n) = y(n-1) + ((x(n) - y(n-1))/slide)
> I understand that there is a degree of feedback over time whose
> intensity of light/dark is controlled by slide_up and slide_down
> controls, but quite how it's done is not quite clear yet!
Gary Nelson's explanation does as good a job as any
of explaining what's happening without making direct
reference to numbers. The object is performing the
calculation above on each individual plane/cell of a
movie; remember that the type of data that the calculation
is being performed on is arbitrary - I could be sending
it 1-plane matrices (or lists, to put it another non-Jittery
way), You'll notice that the help file tells you that the
object supports all data types and planecounts. That's
what that means.