Hi David
I'm having a devil of a job getting the Line function to work as I thought
it was supposed to.
It doesn't draw a line of varying width. Instead it draws a line of
constant wide and varying intensity.
I checked the example you sent.
1. You define the varying color yourself in the Gradient vsl effect.
2. The reason why line width does not vary wrt. image y dimension is that
for antialiasing reasons, the line effect uses a little region around the
current pixel to determine the width. Why? The outline mode rendered,
single pixel wide object edge usually contains some pixels on top of the
object and some pixels just outside the boundary of the object. Try drawing
two hair lines of different colors approximately on top of each other in
Windows Paintbrush to see a similar effect. That's why the Line effect
applies the little region filter first.
Anyway, every (originally black) outline pixel has a full width (white
background) neighbor pixel. Therefore, line filter uses maximal width
everywhere.
I hope this information makes sense to you.
To get around the problem, do not write outlines to the color channel, or
use another channel than color to determine the width.
BTW, V6 post effects have new filtering etc. options for effects like this.
Kind regards,
Vesa
