# A smooth scrolling

hum… surely thats a beginner trick, but could someone explain me why there is a kind of step effect , and how to fix it ?

cheers ;-)

smooth scrolling.v4p (9.8 kB)

smooth scrolling2.v4p (9.7 kB)

thanks west it works.
a long time we didn t tchat ! a lot a lot a lot of work, hope we can find time some days!

but that doest explain me the cause of the step effect not present on Y but present in X ?
any rational mathematical reason ?

(lastslice - firstslice) > step size

means there is simply a big jump from the first to the last slice of a linear spread. with the phase pin you shift this jump around in the spread…

hello tonfilm.
hum…
it makes senses, but here, if i try to cheat phase, that doesn t act on X transform spread…
neither on phase of LFO, nor on phase of Linear Spread ( wich was the one i think you are talking of).

should i use to have a smooth without end thing only a circular spread, as west suggested ?

or should i calculate phase like

smooth scrolling_3.v4p (10.2 kB)

Your X is moving from left to right, an LFO is moving from 0 to 1 and than it jumps back to 1. Now, because off the LFO you used for the X-axis spread, is moving in a different speed than your Y speed, there will be occasions that the LFO ‘jumps’ back in the middle off your screen. (I attached your modified patch, so you can see all the quads in 1 screen.

You cannot use a LINEAR spread to get this behaviour, UNLESS you use some kind off trick that makes your jump go away.

The WAVESHAPER is mostly used for this (set to sine it produce same result as circulairspread) but even a Linearfilter will remove the jumpiness.

You cheated the Y-scrolling jumpiness by zooming!! *or scaling

scrolling4.v4p (25.1 kB)

hi west ! damned me !
didnt think of wave shapper on distance.
how stupid am i !

many thanks , sir !

how is C#?