Full Circle Magazine FR

Over the course of the previous 21 articles, I've introduced the majority of the tools on Inkscape's main toolbar. There are a few, however, that have yet to be described. This is mainly because I've found them to be less than useful to the work I do with Inkscape, but you may find them invaluable. As usual, the only way to know is to use them yourself, so, over the next few instalments, I'll do my best to give them a fair introduction, starting with the Tweak Tool (shown right). With the “T” keyboard shortcut already assigned to the Text Tool, the recently added Tweak Tool has had to make do with “W” (or Shift-F2). It's purpose, as suggested by the name, is not to draw or create new objects, but rather to tweak existing ones. Its tweaks fall into three separate modes: objects, nodes and properties. The user interface doesn't really distinguish between them, but without understanding this hidden distinction, it's easy to become confused about what the tool actually does. Objects: The Tweak Tool can be used to move, rotate and scale individual objects on the canvas. Nodes: When used on a path, the tweak tool can be used to move nodes around, sculpting the path shape in ways that can be difficult to do with other tools. Properties: The tool can be used to change the color of objects and the amount of blur applied to them.

Tout au long des 21 articles précédents, j'ai présenté la plupart des outils sur la barre d'outils principale d'Inkscape. Toutefois, quelques-uns doivent toujours être décrits. C'est en large partie parce que je les ai trouvés moins qu'utiles pour ce que je fais avec Inkscape, mais vous pourriez les trouver précieux. Comme d'habitude, vous ne pouvez le savoir qu'en les utilisant vous-même. Ainsi, pendant les prochains articles, je ferai de mon mieux pour les présenter objectivement, à commencer avec le « Tweak Tool », qui « ajuste les objets en les sculptant ou en les peignant » (à droite).

Puisque le raccourci clavier « T » est déjà pris par le l'outil texte, l'assez nouveau Tweak Tool a dû se résigner à utiliser le « W » (ou MAJ-F2). Comme son nom le laisse entendre, il ne dessine ni ne crée de nouveaux objets, mais fait des ajustements sur ceux qui existent déjà. Ces ajustements peuvent être classés dans trois modes distinctes : celui des objets, celui des nœuds et celui des propriétés. L'interface utilisateur ne les différencie pas vraiment, mais sans comprendre cette distinction cachée, il est facile de se laisser troubler à propos des fonctions exactes de l'outil.

Objets : Le Tweak Tool s'utilise pour déplacer, pivoter et redimensionner des objets individuels situés sur le canevas .

Nœuds : Utilisé sur un chemin, l'outil peut déplacer des nœuds et sculpter la forme du chemin dans des façons qui seraient difficiles à faire avec d'autres outils.

Propriétés : L'outil peut changer la couleur des objets et leur quantité de flou.

Before diving in to describe the individual tweaks that the tool offers, we first need some objects to experiment on. Create a few small rectangles, circles or stars on the page in a fairly random arrangement. A quick way to do this is to draw one, then drag it around whilst “stamping” it onto the canvas using the Space bar. Whatever approach you take, you want to create a random cloud of objects. For my example, I've dialled down the randomness by using Extensions > Render > Grid… on a larger rectangle before manually placing my objects. This is simply to make the sometimes subtle effects of the Tweak Tool stand out better. Before using the Tweak Tool you first have to select some objects for it to work on. Select some of your cloud of objects, but leave a few unselected (or deselect them with a Shift-click afterwards). Now switch to the Tweak Tool using the toolbar icon or one of the keyboard shortcuts, and take a look at the tool control bar (shown below). The Width slider sets the size of the tool, and is reflected by a circle around the cursor on the canvas. This circle can be thought of as being like a soft brush in a bitmap editor – the effect is strongest at the center, lessening gradually as you move out towards the circumference. Large sizes allow you to change many objects or nodes at once, though smaller sizes provide finer control. The Force slider allows you to set the strength of the tweaking effect.

Avant de commencer à décrire les ajustements individuels proposés par l'outil, nous avons besoin de quelques objets sur lesquels nous pouvons faire nos essais. Créez quelques petits rectangles, cercles ou étoiles au hasard sur une page. vous pouvez ce faire rapidement en en dessinant un/une puis en le glissant, puis le « poinçonnant » sur le canevas avec la barre Espace. Quel que soit votre approche, vous voulez créer un nuage aléatoire d'objets. Pour mon exemple, j'en ai réduit le caractère aléatoire en me servant de Extensions > Rendu > Grille… sur un rectangle plus grand avant de placer mes objets à la main, pour, tout simplement, faire mieux ressortir les effets du Tweak Tool, qui sont parfois assez subtiles.

Avant d'utiliser le Tweak Tool, il faut sélectionner quelques objets à ajuster. Sélectionnez une partie de votre nuage d'objets, tout en laissant quelques-uns désélectionnés (ou les désélectionnez après avec MAJ-clic). Ensuite, choisissez le Tweak Tool, au moyen de l'icône sur la barre d'outils, ou d'un des raccourcis clavier et examinez la barre de contrôle de l'outil (voir ci-dessous).

Le curseur Épaisseur règle la taille de l'outil et se voit dans le cercle autour du curseur sur le canevas. On peut considérer ce cercle un peu comme un pinceau dans un éditeur de bitmap - l'effet est le plus fort au centre et s'estompe graduellement quand vous allez vers la circonférence. Les grandes tailles vous permettent de modifier de nombreux objets ou nœuds en une seule fois, mais les petites tailles vous fournissent un meilleur contrôle. Le curseur Force vous permet de régler la force de l'ajustement.

It's possible to change the width and force using keyboard shortcuts, even while drawing. The Left and Right arrow keys change the width, while Up and Down change the force, and the Home and End keys move the width slider to its extremities. If you're using a pressure-sensitive graphics tablet, significant control of the force can be achieved by enabling the button to the right of the slider, allowing you to control the strength of the force parameter with pen pressure. The Mode section contains buttons to select the specific type of tweaking operation you wish to perform. These are radio buttons – only one can be selected at a time. The first six buttons affect objects, the next four affect nodes, and the last three change properties. The Fidelity field seems to apply only to the node editing tweaks, despite remaining enabled when the object tweaks are selected. The Channels radio buttons apply to the two color-related property tweaks, and remain disabled for all others. Starting from the left, the first of the object tweaks simply moves the selected objects around when they're touched by the tool. Selecting a few of the test objects and randomly scribbling around with the tool results in something like this: If you move the cursor slowly, or have the force set high, you can use this mode to push objects around indefinitely. By quickly swiping over objects with the force set low, you impart just a small nudge to their positions with each pass.

Vous pouvez modifier l'épaisseur et la force avec des raccourcis clavier, tout en dessinant. Les flèches Gauche et Droite modifient l'épaisseur, alors que Haut et Bas modifient la force ; les touches Début et Fin déplace le curseur épaisseur à ses extrémités respectives. Si vous utilisez une tablette graphique sensible à la pression, vous pouvez contrôler la force de façon significative en activant le bouton à droite du curseur, ce qui vous permettra de contrôler le paramètre force avec la pression de votre stylet.

La section Mode contient des boutons vous permettant de sélectionner le type d'ajustement que vous voulez faire. Ce sont des boutons radio et vous ne pouvez sélectionner qu'un à la fois. Les six premiers ajustent des objets, les quatre suivants affectent des nœuds et les trois derniers modifient des propriétés. J'ai l'impression que le champ Fidélité ne s'applique qu'aux ajustements de nœuds, bien qu'il reste activé quand les ajustements d'objets sont sélectionnés. Les boutons radio Canaux s'appliquent uniquement aux deux ajustements de propriété en rapport avec la couleur et restent désactivés pour les autres.

À partir de la gauche, le premier ajustement des objets déplace tout simplement les objets sélectionnés quand vous mettez l'outil dessus. Si vous sélectionnez quelques-uns des objets d'essai et gribouillez de façon aléatoire avec l'outil, le résultat sera quelque chose comme ceci :

Si vous bougez votre curseur lentement, ou augmentez le réglage de la force, vous pouvez utiliser ce mode pour bouger des objets à l'infini. Si vous passez votre souris rapidement sur un objet avec la force réglée au plus bas, vous ne donnerez qu'une petite poussée à chaque fois.

The second radio button invokes a different move mode. In this case the objects are moved towards the cursor, or away from the cursor if the Shift key is held. This is best demonstrated using a very large width setting, so that all the selected objects are within the tool's brush area. By slightly moving the cursor at the middle of the grid, you can see that the selected objects have all moved towards the center (see image below left), while the image below right shows the effect with the Shift key held. The third tweak tool moves the selected objects randomly – that is, by a random amount in a random direction. The maximum distance is constrained by the force setting. This tool can be used with a large width brush to affect many objects at once, but can also be used to more subtle effect with a small width to introduce just a little randomness into the positions of a few of the selected objects. The fourth tool shrinks objects, or grows them if you hold Shift. Again, a large width can be used to shrink or grow several objects at once, while a smaller brush allows you to modify things with more selectivity. For this example I chose a small width, then wandered around my selected objects pressing and releasing Shift in order to shrink some, grow others, and leave the unselected objects at their original size. The last of the object-related tweaks changes the rotation of your selected objects. The default is to rotate them clockwise, but as you may have guessed you can hold Shift to rotate them anti-clockwise instead. The Force parameter sets the speed at which the objects will be rotated, though there's no mechanism to constrain the amount to ensure just a little variation, nor to rotate by a random amount to produce more radical results in a single swipe.

The last of the object tweaking tools is, in my opinion, one to avoid. It duplicates the selected objects as you draw over them, or deletes them when Shift is held. Unfortunately, each duplicate is placed perfectly on top of the original, so if your original object is opaque it's impossible to see how many duplicates have been created. It's too easy to accidentally create many hundreds of objects with this mode, especially if the force parameter is large. If you want to create a small number of duplicates then Edit > Duplicate (Ctrl-D) is a better option. For lots of duplicates, Inkscape's “Create Tiled Clones…” dialog is a better option. Even the deletion mode of this tweak is equally well served by the Eraser tool. Clones and the Eraser tool will be described in more detail in future articles.

I'm going to skip over the node tweaking tools and return to them next time. I'm jumping straight to the three property tweaks because these are applied to selected objects rather than nodes, so I can continue to use the same example image to demonstrate their use.

The first of these tweaks is the eleventh mode button on the toolbar. Its tooltip claims that it “Paints the tool's color upon selected objects”, but in my experience it's a little buggy (at least on my 0.48.4 installation). The tool's color can be found at the top right of the tool control bar, to the right of the “Channels” buttons. In theory, it should be possible to set the fill and stroke for the tweak tool while the color button is active, either using the palette at the bottom of the screen, or the Fill and Stroke dialog. In practice however, it's possible to set a fill color, but doing so will set the stroke to black. Setting the stroke to a color will set the fill to “None”, which has the same effect as having it set to black when you actually use the tool. When used on objects that have only a fill, it can be used to change the fill color without modifying the stroke. When used on objects that have only a stroke, it can be used to change the stroke without modifying the fill. But if your objects have both, be very careful when using this tweak unless you want one or the other to tend towards blackness. ===== 6 ===== With that warning out of the way, using the tool is as simple as selecting the mode button, picking a target color, then painting over the selected objects. They will incrementally change towards the selected color, with the speed of the change being determined by the tool's force setting. If you hold the Shift button, the inverse of the selected color will be used as the target. This also applies to the errant black fill or stroke, which will become a white target instead.

The penultimate button also affects the color of the selected objects, but does so by randomly jittering the color values by a small amount. As you might expect, the maximum size of this amount is set by the tool's Force. For both these color-changing tweaks, you can further limit the effect using the Channels buttons, labelled H, S, L and O, which correspond to Hue, Saturation, Lightness and Opacity respectively. If you want to randomise the opacity of your objects while keeping their colors intact, for example, you should disable all but the O button before painting with the tool.

The last tweak changes the blur of the selected objects, increasing it as you swipe over them, or decreasing it when the Shift key is held. This is best used with a small value for the Force parameter, otherwise it's easy to blur objects so quickly that they virtually disappear into a puff of smoke – or rather into a slight smudge that's barely visible on the screen. ===== 7 ===== The image on the following page shows all three of the property tweaks applied to the test image. The target color for the first test was bright green, resulting in bright pink for the inverse color. Compare this “directed” change of color with the more random selection in the second image. The third example shows different levels of blur as the result of setting a small Force value and drawing repeatedly over several of the objects.

Between the “objects” and “properties” modes, the tweak tool offers a wide range of ways to add a little variation to otherwise homogeneous collections of shapes. Unfortunately it's not possible to combine multiple tweaks at the same time in order to move, rotate, shrink, color and blur some objects all in a single operation. Being able to do so would make more sense of the duplicate mode – consider duplicating and randomising the position at the same time – but the tool offers no such facility, somewhat neutering its object manipulating abilities. Where the tweak tool is perhaps at its most useful, however, is in dealing with nodes in a path, which will be the subject of the next part of the series.**