Piranesi 4

I last reviewed the architectural rendering program, Piranesi, close to two years ago, in the September 2002 issue of Cadence magazine (see the review of Piranesi 3). Since then, things have been relatively quiet on the Piranesi front, except for the release of a Macintosh version of the application, which was exhibited for the first time at the Macworld 2004 show in San Francisco (see AECbytes Newsletter #4 on Macworld 2004). The developers, Informatix Software International, have obviously spent the time between releases well, as the new release, version 4, is packed with over a 100 new features. This review provides a comprehensive overview of the application for those who are not familiar with it, and looks at the key new features in the latest release.

Overview of Piranesi

Piranesi is a unique application specifically designed for architectural sketch rendering that understands depth and perspective. If you export a 3D scene to a traditional image-editing program like Adobe Photoshop in formats such as TIFF, JPEG, and so on, the scene gets flattened out to a 2D image. In contrast, Piranesi uses its own proprietary EPix (Extended Pixel) file format in which each pixel in the image stores depth and material information in addition to color. This allows the application to identify the individual 2D planes making up a 3D scene and restrict the application of a color or texture to a selected plane. It also automatically adjusts the size of a texture along the plane according to its depth. So, for instance, if a brick texture is applied to a wall in a perspective view, the tile sizes will automatically recede along the vanishing point of the view. With this base functionality and a host of material textures, filters for special effects, and libraries of various entourage elements, Piranesi allows you to take a plain, computer-generated 3D scene or 2D drawing and transform it into a sophisticated, artistic-looking rendering, in varied styles reflecting different moods (see Figure 1).

The starting point for Piranesi is a 3D model created using any conventional modeling application, flat-shaded with lighting and viewpoints set as desired, and saved in the EPix file format. The latest versions of many modeling applications such as MicroStation, ArchiCAD, form.Z, SketchUp, and Art.lantis support Piranesi directly by generating EPix files. For other applications such as 3DS Max, Autodesk VIZ, and Autodesk Architectural Desktop, plug-ins to create EPix files are available. For other applications, a separate product called Vedute that is supplied with Piranesi can be used. It reads basic file formats such as DXF and 3DS, and allows you to set up the viewpoint and lighting in the model before saving it in the EPix format.

Once you open the EPix file in Piranesi, you can start adding colors, textures, and various kinds of entourage to the scene. The application has a very concise toolset with only 9 tools-Brush, Pen, Painter, Local Fill, Global Fill, Multiple Fill, Pan, Zoom, and Montage-located in the top corner to the left of the graphics window (see the interface illustration in Figure 2-a). It is the extensive number of options associated with each tool that give the application its power and broad range of functionality. Many of these options are located in the left panel just below the toolset; the others are contained in the Tools Manager panel located on the right. The other significant component of the interface is the Style Browser, shown below the graphics window in Figure 2-a, which provides quick access to different paint and brush styles, textures, effects, and "cutouts" (the term for entourage elements in Piranesi).

The basic toolset of Piranesi is quite similar to that of a paint program. What makes it different, and a lot more powerful, is the "locks" feature. Setting a lock restricts the application of a color or texture to a specific area of the scene. There are four kinds of locks: the Plane lock, which restricts the painting to pixels in a particular plane; the Orientation lock, which broadens the painting to all the planes with the same orientation; the Material lock, which restricts the painting to all surfaces with the same material; and the Color lock, which restricts the painting to all surfaces with the same color. Thus, if you activate the Global Fill tool and the Plane lock and select a point on the scene (see Figure 2-a), the program automatically detects all the pixels contained in the same three-dimensional plane as the first point, and applies the current paint style to them (see Figure 2-b). If you were to repeat the same action with the Material lock selected instead of the Plane lock, the scope of the paint would be extended to all the surfaces that have the same material definitions as the first point (see Figure 2-c). The material definitions for each pixel in the scene come from the application in which the model was originally created, and can be seen in the Information Bar located above the graphics window. Note that in the example shown in Figure 2, the blend type was set to Overlay rather than the default of Paint so that the lighting and shadows on the walls are not lost.

Once you have rendered all the surfaces and applied a background image to the scene, you can add life to it by placing cutouts with the Montage tool. Piranesi comes with an extensive library of cutouts accessible through the Style Browser, including those of people, animals, vegetation, and street furniture. The cutouts are automatically sized to scale, depending upon the scale of the model and the position of the cutout; so the further away you move the cutout from the eye position in the scene, the smaller it gets. Cutouts are also masked, which means that based on the position of a cutout, parts of it will automatically be hidden by objects in front of it. In addition, cutouts can also cast shadows in a specified direction, which adds to the realism of the rendered scene (see Figure 1-b).

Rounding up the repertoire of the program is the ability to apply different effects to the scene, such as pencil sketching, soft painting, sepia etching, line drawing, and so on, by using various kinds of filters (see Figure 1-c). You can work with panoramic views and export the resultant rendering as a QuickTime movie, which allows an end user to move around the panoramic scene in real time. You can even paint 2D images such as plans, section, and elevations, converting plain drawings into artistic renderings. Piranesi also provides support for more photorealistic renderings, such as the one shown in Figure 4 in the next section, by providing tools for creating illumination and adding reflections and highlights to the scene.

Let's move on to look at what's new in version 4 of this application.

Key New Features in Version 4

One of the most significant new features in Piranesi 4 is the ability to use 3D models and RPC Smart Content files as cutouts. This means that the cutout can be rotated to view it from any direction and angle, and then rendered as required. These 3D cutouts can be created from a variety of 3D file formats including 3DS, DXF, Sketchup's SKP, MicroGDS' MAN, and GDS's THF. Thus, manufacturers' furniture and fixtures content posted online, for instance, can now be easily be brought into Piranesi (see Figure 3). While support for Archvision's RPC (Rich Photorealistic Content) was available in the previous version, it has been upgraded to work with RPC Smart Content, which provides more control over key features of the content. For example, a Smart Content RPC car can be manipulated by turning the tires and tinting the windows. The controls that are available to manipulate a model will vary from file to file.

With the introduction of 3D cutouts, Piranesi 4 also provides more options for manipulating them. You can choose how colors and materials are assigned to 3D cutouts, and whether smoothing is applied to curved surfaces. The "tweak" operation-moving or scaling a cutout-has been extended for 3D cutouts to allow them to be resized in three dimensions as well as rotated (see Figure 3). In addition, all types of cutouts can be clipped, sheared, or placed at a specific distance from an existing surface. Multiple cutouts can be selected and moved, resized, or rotated together. Floating cutouts are now stored in the EPix file, so when the file is re-opened, the cutouts are automatically restored exactly as they were, including their positions, visibility, and shadow settings. In the previous version, if you did not save cutouts to a file or "burn" them into the scene, they were removed when the file was closed. Another new capability is being able to import cutouts from one EPix file into another.

Piranesi 4 makes it easier to add signage to a scene with the new capability to specify a depth for text cutouts, giving them a 3D effect. Text cutouts can also be offset from a surface by a specified distance. Support for Unicode text has been added, making it easier to include characters from different languages.

In my review of the previous version of Piranesi two years ago, I pointed out, as one of its limitations, that the interface could be simpler and more intuitive to use. I was pleased, therefore, to find that the new version has several interface enhancements designed to make it easier and quicker to use. The Tools Manager panel located on the right, which was mentioned in the previous section, is one such enhancement. It combines several dialog settings that were located in six separate windows in the previous version, providing more screen real estate for the graphics window (see the interface diagram in Figure 3). Also new is the Information Bar located above the graphics window by default, which provides salient information about the current pixel such as its material and coordinates. Other interface enhancements include the ability to define custom keyboard shortcuts, which will allow experienced users to speed up their work; redesigned tool icons; additional display of useful information in the status bar; and the ability to zoom views by any factor.

Piranesi 4 also provides a wide range of new effects and settings. Two new illumination fades are available for night-time or indoor scenes: Cone fade for creating an impression of spot lighting (see Figure 4); and Strip fade, for creating the impression of strip lighting. Illumination and radial fades can now be tweaked after application, making it easier to experiment until the desired effect is achieved. Seven new filters are available to refine an image, allowing for the adjustment of color, hue, brightness, contrast, sharpness, smoothness, and so on. Painting has been enhanced with a new bristle brush with the ability to set the number of bristles, and a new dynamic setting option that introduces selected random elements into the stroke to increase the hand painted effect. For example, a painted stroke can now have a variation of color spread instead of just the current color. Brush sizes and painter mark lengths can now be specified as a percentage of the document width, useful for setting up styles that can be used with different resolution EPix files.

Piranesi's already extensive library has been expanded with the addition of over 300 new cutouts, texture images, and styles, including 3D cutouts of common indoor and outdoor objects and several basic shapes; additional people, including a new Groups category; a number of new sketch cutouts; a greater range of vegetation, including a Tropical category; many new sky textures; and new sponge brush styles for use with the Brush tool.

 Another limitation that I had pointed out in my review of Piranesi 3-the lack of video tutorials, which would have made the application easier to learn-has been addressed in this release. Several video tutorials are now available to explain the use of different features of the application. The range of written tutorials has also been expanded. Beginners should now have adequate support to be able to learn the application on their own.


Piranesi is a unique and innovative application that has no real competitor in the AEC industry. It is the kind of application few professionals could have even envisioned. Most visualization experts traditionally use high-end rendering applications to create highly photorealistic renderings, or at the other end of the spectrum, import a rendered image into an image-editing application like Adobe Photoshop and apply filters to it for hand-drawn, water color, and other effects. It is difficult to find any limitations as such in an application that presents you with a functionality you had never imagined. Most architects when introduced to Piranesi for the first time-this includes students at UC Berkeley I have taught the application to-are simply wonder-stuck by it.

While you don't have to be an artist to use Piranesi, you do need to have an artistic sense to produce good results with it. And as I pointed out in my review of Piranesi 3, it takes time to learn to use it well. The enhancements in Piranesi 4 certainly make it easier to learn, but there are no shortcuts to producing a good rendering-you have to sit down and experiment with all the tools, settings, and effects to figure out how to best apply them to get the result you want. Once you have done that, though, it would be a breeze to generate rendered perspectives of proposed designs for client presentations, brochures, posters, and so on-work that would have traditionally been outsourced to professional artists. This can lead to considerable cost savings for an architectural firm, given that the cost of the application is a modest $750. Besides, it is a lot of fun rendering with Piranesi, a welcome change from the complexities of actually creating the 3D model in a traditional CAD or BIM application. Piranesi is an application that the artistic side of a designer can truly revel in.

The challenge before Piranesi is how to become mission-critical rather than simply remain a "would be nice to have" application. While the actual modeling of the building is usually seen as mission-critical, the same is not true for artistic-looking renderings of the kind that are Piranesi's forte. To make the application more compelling, Piranesi needs to also include enhanced photorealistic rendering skills that are on par with those in other modeling and visualization applications. It can then become the must-have single "killer app" that addresses all kinds of renderings needs-from the schematic to the artistic to the highly photorealistic-at different stages of the architectural design process.

About the Author

Lachmi Khemlani is founder and editor of AECbytes. She has a Ph.D. in Architecture from UC Berkeley, specializing in intelligent building modeling, and consults and writes on AEC technology. She can be reached at lachmi@aecbytes.com.

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