how does brush angle jitter work?

[keystrike]

I am exploring angle jitter for brushes in the latest PS CC. I am using a brush which is a 1 px thin horizontal bar at width of about 160 px, and I draw across or down, producing a chain of bars at various angles. In this exercise, the only brush setting is for angle jitter.

(1). Is the following correct?

When control is off, for angle jitter setting of x%, it seems that, for each separate stroke, the angle is mostly plus/minus 8% (of something) or  0 relative to an invisible horizontal line across the drawing surface, independent of stroke direction. (So the bar is either horizontal, or tilted somewhat up and down regardless of stylus movement).There are other angles. but these seem to me to appear less (I may have a biased eye.). So each angle is a sample from a fixed distribution which seems to have peaks in the middle and at the ends. (Hard to know exactly.) This is useful.

In any event, when control is set to "pen pressure", it behaves completely differently. The angle seems to take a random walk in a circle, with the "step size" given by x% of something. This is very different, as now all angles appear and the draw stroke is, for me, most unintuitive and less useful.

(2). Can I do the following?

It seems to me that, with pen pressure, the angle still should be drawn from a fixed distribution,where the width of that distribution should depend on pressure. Then, with low pressure, there are only small angles, and with larger pressure, there are larger angles but the angle still bounded depending on the jitter setting and having the same (scaled) distribution. It would also be very nice if the angle could always be perpendicular to the pen direction (which is effectively what happens for a vertical stroke.)

Thank you.

[Chuck Uebele]

Top stroke is normal line brush - no other setting other than spacing. The next one down is with the angle set to 90 deg.

Next line down is with jitter set to 8%. in makes the line angle different. The last line is with the jitter set to 0 and the mode set to pen pressure, you can see that with added pressure though the stroke, the line angle changes. If you have any jitter set, it will also fluctuate the angle, which is what I suspect you're getting.

[keystrike]

Thanks, but this does nhot address my questions.

[Chuck Uebele]

So what else do you want to know? You can either change the angle of the brush to 90 deg to get it always vertical, or whatever angle. If you want it always in line with the stroke of the pen, then you have to use direction and pen pressure isn't use, so if that's what you're asking, you can't have both.

[Semaphoric]

To get the brush to be perpendicular to the stroke, set the rotation to 90° under Tip[ Shape, and angle to Direction is Shape Dynamics