Pressure profiles Affinity Designer

[candacew]

I do not understand how pressure profiles work in Affinity Designer. 

 

I have created and saved pressure profiles in the Stroke panel, located by default in the upper right corner with the Colour and Brushes panels. When I select a brush and click on the More tab in the brush controls, these profiles are not visible. There are four Standard profiles from which to choose.

 

I am referring to the Vector Brush Tool.

 

Does the Pressure profile in the Stroke panel control a different parameter or a different tool?

 

Also, if I modify a brush to add size variance, I have to change the Controller to Pressure. Understood! But, if I change to another brush, the Controller stays on Pressure, even though the second brush has no variables to change. It seems to me that this should be brush specific.

 

I apologize if I have used incorrect terminology, but I hope that I have been clear. I want to understand the brush and stroke controllers-what they control, which settings are universal and which are specific, etc.

 

Thank you!

[F_Kal]

Hmm, they are something quite different, and I think the name is adding to the confusion.

For the sake of the conversation, I'll call Pressure Profile, the little Pressure graph that can be found in the Stroke Panel. The graph found in the Brush Selection window (for instance by going to the Vector Tool toolbar-> More) I shall call it simply "a pressure curve".

 

1.The Pressure Profile (Stroke Panel)

The Pressure Profiles found under the stroke panel, are modifiers of some variable called "Pressure". Every curve/shape can have a pressure profile, but only the ones created by the Vector brush tool have a real pressure profile that was generated through recording the pressure of your tablet's stylus! If you haven't noticed, whenever you create a brush-stroke with the Vector Brush tool, AD records a pressure profile for you: It logs the pressure you apply as you draw the stroke. 

All shapes/curves (ellipse, star, rectangle, path tool, line etc), may have an artificial pressure curve if we so wish, but not necessarily. We may wish to give them one if we want them to appear "hand-drawn" for instance.

What is important to understand is that, this pressure profile depicts the pressure in relationship to the distance from the beginning of the curve. In other words, it's a Distance-to-Pressure curve. (unlike the pressure curve, that is a Pressure-to-Width curve and is being explained below).

 

2.Pressure curve (Brush - Selection)

On the other hand, the "Pressure" curve found in the Brush - Selection window (eg. under the Vector Brush Tool -> More settings or under the Stroke Panel -> Properties...) tells us how this pressure profile will be mapped/translated into width/size (or opacity)! This curve, is a Pressure-to-Width curve.

 

They complement each other, but are not the same! If for instance you choose Size Variance: 0% or you turn your pressure curve into a horizontal line, no matter what "data" your pressure profile contains, the stroke will have a constant width. Similarly, if the shape/curve's pressure profile is a horizontal line (constant) then no matter what the pressure curve for the assigned brush is, your stroke will have a constant width.

 

Some things to consider about the pressure curve (Brush - Selection)

- this curve is often useful to neutralize some drawing habits we have (eg. a heavy hand, a light hand, an unstable hand etc)

- it's also useful to emulate the different dynamics in the behavior of various drawing tool (eg. pencils with different hardness - 2B/HB, different charcoals, different brushes)

- it can be programmed to affect the opacity of a stroke

- Personally (somebody correct me if I wrong) I think the pressure curve in the Brush Selection window, is useful for hand-drawn brush-strokes through the Vector Brush Tool exclusively, where we are trying to compensate for our hand's lack of absolute control. For Pressure Profiles that were artificially created in the Stroke Panel, a 1:1 (linear) profile is enough: all the different width/opacity effects can be simulated through that (correct me if I'm wrong)

 

Hope this helps

 

[JamesDavis713]

why cant i save the stroke pressure profile in the application and not just  the document?

 

[MEB]

Hi JamesDavis713,

Welcome to Affinity Forums

The only way(s) i know to save it more permanently is to either save the line with the profile as a default (with the object selected go to menu Edit ▸ Defaults ▸ Save) - which means lines you create on new documents will all use that pressure profile, which may not be desirable - or create a style from the line with the profile (from the small menu icon on the top right of the Styles panel Add Style from Selection). You can then change the the lines to that profile simply clicking on the respective style int he panel.