Snapping handles to 45° (or custom angle)

[Alphons]

Hi there,

 

I'm searching for a way to snap curve handles to 45° (or better to a custom angle).

Is there any way I didn't find or isn't it possible yet?

 

Thank you advance,

Marco

 

 

[MEB]

Hi Marco

Welcome to Affinity Forums.

It is not possible yet. Only to 90º for now.

[Alphons]

Oh what a pity, hopefully it comes with a further update because I'm not able to draw in Illustrator anymore without the use of abusive language.

And thanks for this fast answer.

[Ben]

We have plans for this already. I'll probably add it as user defined axis, which will also provide isometrics options, etc.

Currently, you can drag out a new handle or redrag an existing handle using the Pen tool and constrain to 45 degrees by holding Shift. Our snapping currently only works on X and Y axis... This will include custom axis at a later date.

[rui_mac]

Custom constraining angles will be great :-)

[MaxClass]

Alphons,

 

Being an Illustrator user since 1987 v1.0 I can say that almost without exception Bezier handles hardly ever need to be anything other than vertical or horizontal. Doing otherwise will alway give you a bounding box that is larger than the curve(s) you are drawing.

 

In addition, all top notch font designers never create handles that extend beyond the extents of the graphic. A bounding box for any glyph will never extend beyond any part of the character. In teaching many many users how to handle this type of drawing the best examples are to take any fancy font, convert any character into outlines and then study where the font designers place their Bezier handles on all curves. Almost all will be place at the 12, 3, 6 or 9 o’clock positions and will always be either vertical or horizontal. Obviously there will be some exceptions. Another example is to simple draw an “Oval” or “Rounded Rectangle” and look at the placement of the Bezier handles that AD put there.

 

Max

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[MaxClass]

Bezier Curve Placement of Points

 

After years of playing with Bezier Curves and dealing with the algorithms that draw them I learned a few things about them from the inside out.

 

The algorithms generally create the curves using a series of straight lines to draw them however small.

 

A Bezier Curve should be drawn so that the end nodes and the handle nodes break the curve into approximately three (3) equal segments (the 1/3 Rule). This will allow the algorithms to produce approximately the same number of segments between all nodes and give the smoothest possible curves.

 

If you have a 10 inch curve and one handle is one inch from the first node and the next bezier handle is eight inches from the last node the curve should probably be broken up into more than one segment as the algorithm will not distribute the individual line segments evenly. In fact they will be bunched up on the short handle end and spread out on the long handle end.

 

Using the 1/3 rule you will find the end results of your curves looking great. Again, looking at font characters you will typically see the same pattern used there too by the best font designers.

 

Hope you find this useful. 

 

Max

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[MattP]

Hi Max,

 

We use an adaptive expansion so it doesn't matter how you form your Bezier segments - the correct amount of subdivision will happen on all areas of the curve so there would be no 'bunching up' of nodes towards one end and the curve would always be perfectly smooth at whatever size it is asked to draw.

 

I also saw an interesting article the other day that was basically encouraging all designers to only ever use axis-aligned node handles - stating that the results you achieve are more visually pleasing - and I have to say it was very compelling!

 

Thanks,

Matt

[rui_mac]

I first met Bezier curves (and more kinds of parametric, quadratic curves) when I was only 18 years old. I'm almost 43 now so, I may say that I know these types of curves quite well in most of their incarnations (Akima, Cubic, Beta Spline, etc)

The rule of thumb is not placing nodes at orthogonal/quadrant positions as that would limit the organic look of most illustrations (although that is more true for font design).

The rule is to place the points where a curve changes direction. That means that if a curve is, roughly, going from left to right and down to up, a point needs to be placed when that curve changes from right to left or top to bottom. If any of the directions changes, a new node needs to be placed.

And that's it.

This works even for aproximated curves (not interpolated ones).

The Bezier curves add the convenience of handles but they are just an "extrapolation" of other types of quadratic splines.

[MaxClass]

MattP,

 

Please send me the adaptive expansion algorithm (just kidding). I used something similar in my vinyl cutting software to maintain a set number of points per inch to maintain smoothness when people would scale up AI artwork sometimes over 1,000% or more. Was not unusual to have a single Bezier Curve over 20 inches in length in some sign artwork

 

rui_mac,

 

Nice “Rule of Thumb” explanations and I agree. Where my users used to run into problems though was whenever they would create some artwork that had handles that stuck way out past the actual extremities of the artwork itself. Because Illustrator always saves a “Boundingbox” in every file (which always encompasses every point in the artwork, including handle points) it would give a misleading size to the actual artwork when the file is opened. If a handle is sticking out the left side of a graphics 3 inches and the user scales it up 1,000% then that would equate to 30 inches in the final cut size meaning the actually artwork would wast the first 30 inches of the vinyl.

 

By not creating any handles sticking beyond any portion of the artworks bounding box always solved the problem.

 

In AD the bounding box for any path (like for moving objects) only shows you the bounding box of the “nodes” and not the handles so in essence it is not really a true reflection of the extent of any single path at all times. This can also lead to having some long handle (poorly drawn I would say) ending way outside of the work board area. Not that that will kill your graphic but it is unnecessary to have to do that when keeping handles new the extents of a graphic vertical or horizontal totally eliminates that possibility. Illustrators Bounding Box for he entire graphic always contains all node points and handle points.

 

Of course, in the end it probably all comes down to personal preference but good drawing habits are never a bad thing.

 

Max

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