What's new in Krita 2.9

The newest update to the Krita digital painting application has been released. Version 2.9 introduces several new user-interface features, updates to the layers system, and a variety of tool and rendering improvements. The 2.9 development cycle was also the project's first to be centered around a crowdfunding campaign. In addition to raising funds, Krita's campaign allowed backers to vote on the priority of new feature work. The process was evidently successful enough that the Krita team is planning to use it during the next cycle as well.

The last major Krita release was version 2.8 in March of 2014, which we looked at back at the time. The 2.9 builds for supported platforms are available on the downloads page. Linux users, however, may find that the packages are available early through their distribution or through volunteer-run repositories. There is, for instance, a personal package archive (PPA) for Ubuntu-based systems.

The project started a crowdfunding campaign for the 2.9 cycle on Kickstarter in June, with a €15,000 goal that would be enough to fund one developer to work on twelve features to be chosen (by the donors) from a list of candidates detailed on the campaign page. A stretch goal would have support a second paid developer targeting twelve additional features for the same time period. The project beat its primary goal by a healthy margin (€19,955 in total), which meant the single-developer funding was secured. The project did, however, work on additional features during the development cycle. Backers voted on which features would be implemented, ultimately selecting an assortment of new transformation tools, improvements to the way Krita uses layers and masks, and fixes for some individual tools as the targeted feature set.

As of now, the project has successfully completed eleven of the twelve new features—in an email, Krita's Boudewijn Rempt said that the twelfth will arrive in the first point release following 2.9. It is always nice to see a free-software application have a successful fundraiser, of course, but the Krita campaign is also interesting because of the issues that the backers ranked as being of high importance. Specifically, many of them address transformations and layer manipulation, as opposed to (say) new brush engines. That suggests that Krita's core functionality—natural media simulation—is more-or-less meeting the needs of its users.

More than meets the eye

The transformation tools allow the user to warp and distort image content. The application has long had a standard-issue transform tool that could do skewing, stretching, and the like on a selected region. The new perspective transform is another option likely to seem familiar from other graphics applications; it lets the user distort the selection as if stretching it toward a vanishing point. A particularly nice touch is the red dots that help the user line up the transformation by showing where the vanishing points are. Users can also set up a "perspective assistant" using the ruler tool; the assistant is a grid overlay that provides lines running to the vanishing points so that it is easier to keep transformed objects properly aligned.

The "cage," "warp," and "liquify" transforms are a bit more interesting. The cage tool lets the user draw an arbitrarily shaped selection with straight line segments, then grab any number of vertices and move or rotate the drawing using the mouse. GIMP has a similar tool; it is most useful because the selection cage that the user draws serves to constrain where and how the distortions affect the image. A simple rectangle only has four corners to manipulate, so the content near those corners invariably get more distorted than whatever is in the center.

The warp tool is similar, except that the user chooses control points inside the selection, rather than using the vertices on the outside. Liquify is yet a third variation. Basically, it lets the user perform warp-like transformations anywhere in an image, without having to make a selection first.

The warp and liquify transformations are particularly sensitive to rendering problems; they distort the original image, so pixelated or blocky artifacts can be even more distracting if the transformation happens to enlarge the affected part of the image. Another feature funded by the Kickstarter campaign was to improve the quality of the transforms: the image data is sampled at 4x resolution and there is a new antialiasing algorithm.

Layering and masking

Several changes have been made to how the user works with layers and masks in Krita. For example, the user can now automatically create a mask for a layer that is generated directly from the layer's alpha channel. In other words, rather than trying to select all of the non-transparent pixels in a layer to mask them off, the same selection can be done with one click. Better still, the mask supports alpha transparency, so pixels with an intermediate alpha value get a semi-transparent mask.

Transparency masks are useful for protecting part of a layer from getting accidentally painted over. Krita has had support for the feature for a while, but a new feature in 2.9 is that these masks can be exported and loaded into different documents. That is primarily a feature that regular Krita users will appreciate, since it saves duplication of effort.

Transparency masks are made by painting a black-and-white layer; areas painted white are opaque (masking off the underlying image), while areas painted black are transparent and let the image beneath show through. The various values of gray in between constitute semi-transparent regions.

Finally, the transformation tools mentioned above can be applied to masks and layers, rather than operating directly on selected pixels. In essence, this means that the transformations can be saved as non-destructive operations that can be switched on and off by showing and hiding the mask or layer.

For anyone who is curious, the one new feature that did not land in time for the 2.9.0 release is a related idea. It is also one that will almost certainly be talked about by users who are converts to Krita from proprietary applications: support for "layer styles." A layer style is the ability to apply a "live" filter effect (blur, color adjustment, etc.) to a layer, so that the filter is applied to whatever content is visible from the layers below.

Photoshop has had a similar feature for a while and, rightly or wrongly, critics of free-software graphics applications are quite fond of pointing out specific differences like layer styles as evidence their applications are better. Whatever one thinks about the wisdom of implementing features first seen in proprietary applications, they are often the features that are requested the most.

Editing tools and workflow

Support for working with vector shapes has improved noticeably in the new release. Vector objects can now be rescaled to any size, regardless of the resolution of the canvas in the document. Previously, such scaling was constrained by the resolution of the document, which undermined a lot of the advantages of drawing with vectors to begin with.

Another new feature is support for gradients that follow the shape of an object. Previously, Krita had the usual palette of standard gradient types (linear, radial, etc.). The new gradient type allows for an even-looking gradient that fits into any polygon, selection, or even inside of text.

Krita 2.8 introduced initial support for the G'MIC image-filter system as a plugin. The 2.9 release finally supports the full G'MIC filter set. The user interface is the same as the G'MIC plugin for GIMP, which will certainly please all those who switch back and forth between several applications.

Another interesting change in Krita 2.9 allows the user to have the same file open in more than one window or tab. That means it is possible to see a zoomed-out perspective on the entire document while also working on a specific detail. In fact, the ability to have several images visible simultaneously is a new feature in its own right. The user can have, say, a reference image open in one part of the Krita application and work in another. In previous releases, the user would be able to switch back and forth between image tabs, but this is more convenient.

As is usually the case with Krita, there are far more small changes and updates than there is space to discuss in any detail. There are new color selectors for previously unsupported color models, there is a high-dynamic range painting mode, and there is support for saving and sharing collections of resources (like brushes and patterns) in external files.

Up next, the project plans to initiate another crowdfunding campaign to implement another batch of features—presumably including several from the 2014 fundraiser that have not been addressed yet. But the details of that next development round have yet to be announced; for now there is much for artists to explore in the 2.9 release without also worrying about what might be added further down the line.