Piranesi Review - The American Society of Architectural Illustrators (ASAI)

piranesi review by Informatix Software International

reviewed by Susan Sorger

Pictured Clockwise From Top Left: “Mangrove Interpretation Platform,” Carlos Marrero, Blueboy Digital Design Solutions, Brooksville, Florida “Italian Style Duplex,” Jeff Morgan, VisionJem, Centennial, Colorado “Shanghai Hotel Renovation, Executive Club Reception Entrance,” Drummond Hassan, Young+Wright Architects Inc., Toronto “Interior,” Marco Crawford, London In addition to its ability to generate photorealistic images, Piranesi can be used to produce drawings that simulate those produced in tradtional media such as watercolor, pen-and-ink or marker.

The often wistful requirement of the architectural market, to turn out a simulated watercolor employing digital tools, has spawned what has become the signature Piranesi look [see illustration, facing page, below]. To achieve this look, the software user must begin by importing a 3D model from another program with textures such as brick and other materials already applied. Once imported to Piranesi, entourage elements are then placed and the entire image is flood-filled with a color such as white or cream. One of several Piranesi brushes is then employed to lift away the overlay color to reveal the bits of color and form beneath. The effect can be modified by varying the grain or the brush used or the degree of transparency when lifting. The entire process can even be automated to randomly lift off paint over a given area. The smudgy look that results is evocative of a hand rendered image but with the advantage of taking very little time to produce. What is surprising about Piranesi is that some professional renderers have adopted it to create more nuanced and artful illustrations. In truth the huge variety of tools available in Piranesi are more readily employed with a deliberation typical of a professional renderer than the “get-it-out-the-door” process of the typical architect user. Painting a Piranesi rendering can take four hours or four days. It is as feasible to use it to simulate a marker, watercolor or pen-and-ink drawing as it is to produce a photorealistic image. What makes Piranesi so unique is that its native “Epix” file format carries not only the customary 2D image (the RGB channel to paint on), it also carries a depth channel and a materials channel [see illustration, page 10]. These two additional channels allow an illustrator to isolate areas on which to work and to apply effects with maximum ease. As in Photoshop one can select (or “lock on” in Piranesi lingo) an area by color, but in addition one can also lock on to a specific area of assigned material as well as a specific plane or orientation. It is possible, for instance, to select all of the walls that have a stucco material definition, oriented in one particular direction, but only if they are in the same plane, and apply an effect such as a hint of transparent yellow sunlight. Or one can lock on to all the brick material in the image and refine that further by changing the reddest red in that brick to some other shade. It’s accomplished in a thrice in Piranesi because the hidden material channel indicates each material area by a unique solid color. Should one wish to apply further processing in other software, one may export not only the image, but the material channel as well which can be used for quick and easy masking. Thanks to information in the depth channel, an illustrator may switch between treating parts of the image in a 2D fashion or a 3D fashion. Piranesi holds the height, width and depth information of an image in imperial or metric measurements and understands which structure or item is behind or in front of the next one. One can pull in an entourage element from the very generous library provided by Piranesi or from a third party provider, define it as six feet tall, and place it in the image. Piranesi will immediately re-size it in the perspective’s context by means of the depth channel. You can even scoot that entourage person behind a table or car. The depth channel also facilitates a number of fade effects available in Piranesi. Want a fog that sits three feet from the ground? No problem. Want that brick detail to fade as the building recedes to the background? Also no problem. For a 2D rather than a 3D fade Piranesi can locate based on pixel coordinates. You can create 2D fade effects on any angle that end at a pixel location of your choice.

Pictured from Left to Right: "Southern Retreat," Susan Sorger. An illustration as it appears in the depth channel, the materials channel and the RGB channel. "Fort Myers Retirement Home Renovation," Susan Sorger The textures, painted surfaces and lighting are applied using transparent painting and depth fading techniques over a white model with shade and shadows already in place. The vegetation is from Piranesi’s own collection of stock photos with some Photoshop filters applied. The figures are hand-painted in gouache, scanned, masked out from the background and dropped into the image using Piranesi to auto-size them in perspective.

Because Piranesi can read a form in 3D, it is possible to wrap patterned textures around the form. For example a striped pattern can be wrapped around a spherical shape such as a patio umbrella [see illustration, page eleven]. Had the umbrella been painted or defined as a single material, the striped texture would have wrapped in a way similar to the sphere. In order to mimic the real world construction of the fabric umbrella, a little forethought in the 3D model was employed before exporting to Piranesi. Each section of the umbrella has a different material definition so that a section could be “locked” by material and the design wrapped with a unique skew for each section. Locking by color would not work because the shading of the form creates too many variations of color. Changes can easily be accommodated in Piranesi. Even a completed rendering can easily be changed when a new detail needs to be added. For example, if a new door is added to the original model, a new export with the door in place can be imported to Piranesi. The old rendering can be exported as a raster or image file type and applied over the new import as though it were painted on the surface. Then the painted surface over the new door can be locked on and erased out leaving a new section ready to repaint. Alternatively, one can save each step in the process in a “style library” and apply those steps on the same image or with tweaks to a new image. The entire series of steps can be automated in a multi-fill paint application. Frequently used techniques can thus very quickly be completed in new projects with a minimum of fussing with settings. With Piranesi one can render panoramas, add 2D and 3D lettering, automatically create reflections, and simulate light and shadow. The light and shadow effects are somewhat rudimentary as Piranesi does not use raytracing. Instead, the direction and length of the shadow is mathematically calculated based on the shadows previously imported in the 3D model. To light a scene requires the user to have some knowledge of how to convincingly render lighting effects and to be able to judiciously use certain specific Piranesi brushes and techniques. To some, particularly those doing photorealistic work, Piranesi’s ability to handle light and shadow may be a serious shortcoming. The new Piranesi 4, which will be available in September 2004 in the Windows version (the Mac version is awaiting the release of the latest version of Apple’s operating system) addresses many of the difficulties that users have reported. Cutouts, or entourage elements, have sometimes been difficult to position properly on the ground, but new tools available in version 4 have addressed that. Unfortunately, flat 2D cutouts such as automobiles which cover large areas in perspective, can not be easily placed in any 3D environment . . . and that includes Piranesi’s. A flat image of a car drawn to recede in perspective, will read as a car rearing up on its hind wheels in the 3D world of Piranesi or any other 3D rendering program. Care must be taken even with a cutout of a scale figure whose upstage foot is some distance from the downstage one. The resultant cast shadow would indicate that the upstage foot is a shorter one dangling in the air rather than planted firmly on the ground. Fortunately version 4 will allow 3D cutouts (effectively 3D models) to be added to the rendering. Of course, it would never be an issue if the autos and furniture were placed in the original model, but we don’t all share the same work processes. Also new in version 4 is the ability to tweak cutouts in many new ways, including the simultaneous handling of more than one. Text can now be created in 3D. There are also new user-definable shortcut keys as well as new brushes, filters, spot and strip lighting effects, and an even more extended library of cutouts and textures. Many of the changes are administrative or housekeeping items that improve the overall ease of use. The makers of Piranesi have been very responsive to user feedback in determining the priority for these enhancements. Piranesi is compatible with sixteen different Windows 3D modeling applications and eight Mac applications. It does take some investment of time to learn this program. For those accustomed to using Photoshop, the organization, while far more intuitive, is different enough that it will take some getting used to. Piranesi has the undeserved reputation for having a long learning curve. A investment of three to four days on the tutorials can lead to significant expertise in a relatively short time, but an expectation of working well with it in a matter of hours is not realistic. The new video tutorials on the Piranesi site, however, have gone a long way to facilitating the learning process. Piranesi is unique in the market because it is an application specifically tailored to and targeted at the needs of the architectural illustrator. It is not a replacement for Photoshop or other rendering software, but it does stand out in its class. Susan Sorger, an architectural illustrator in Toronto, owns and operates Entourage Arts, which sells hand-rendered entourage for use in digital renderings. She served as a beta tester for Piranesi as well as SketchUp.

Entourage Arts - Piranesi

Reseller of Piranesi 3d rendering software from Informatix for architectural graphics, architectural images and architectural illustration.

click here for further information