Creating Perspective Grid & Vector Line Art for Cruise Ship Illustration
All Tutorial Text & Images - Copyright © 2011 KHI, Inc.
All of the initial line artwork for this cutaway illustration was done in vector-based Adobe Illustrator CS, created for Royal Caribbean International in early 2001. Most of the final color work for this ship illustration was done in Adobe Photoshop. The techniques used in this demonstration tutorial are applicable to any three-dimensional perspective drawing, regardless of scale or complexity.
This project presented many unique challenges. The actual ship (Radiance of the Seas) was still in Germany being completed for Royal Caribbean when I started work on the project. When I began, there was no photography or CAD reference to work from, only the paper blueprint you see below. In addition, the brochures needed to be completed by the time the ship went into service, therefor, the final illustration had to be finished in two months or less.
The first step was to map out the physical space that the ship would occupy (below) by creating a master perspective grid. By establishing a horizon line and three main vanishing points, an angle was developed that showed the maximum amount of important features on the ship.
Technical Note: This type of angle is generally referred to as a bird's eye 3/4 perspective view. For more information on perspective drawing techniques used in mechanical drafting and architectural drawing, check out the: two-point perspective drawing tutorial.
The next step was to rough in the deck elevation grid, mapping out each deck level location along with three lateral cross section views located at the bow, stern and midship (below). Each deck level was located by using a pre-defined scale of measurements within the master perspective grid, scaled to a specific reduction ratio.
After the master layout grid was complete, work began on the individual decks. Working from the paper blueprint (A), each deck had to be individually redrawn in overhead plan view (B) using Adobe Illustrator CS. To speed up the process, only the details that would show in the finished cutaway illustration were duplicated. Items such as walls, railings, furniture, floor patterns, and measurement scales where grouped together based on their shared attributes.
When all 14 decks had been completed at the same scale, each deck plan was distorted into the master perspective grid using Adobe Illustrator's "Free Transform" tool. Once distorted into the master perspective grid, they provide an "in perspective" floor plan for each level. Common objects and furnishings that are located at the same elevation height were linked or grouped together are raised to their correct height. All vertical and three-dimensional objects were then re-drawn using the distorted floor plans as a location template.
Technical Note: Adobe Illustrator CS (or any other Illustrator version's) "Free Transform" tool leaves much to be desired. Before distorting a grouping of objects, make sure to highlight (activate) all of them and go to: Object>Transform>Reset Bounding Box. This will keep multiple objects from confusing the orientation of the Bounding Box once you start moving and distorting it. For comprehensive information on this and other procedures go to the main tutorials page.
The next step was to decide where to cut away the exterior hull of the ship as well as cutting through each individual deck surface. For the most part, these important decisions are guided by the client as they must decide how best to show the important interior details within each public space on their ship. Once each deck level is in place and cut away in the proper location it is time to start adding dimension to all of the objects located on each level (sample below).
Using each distorted floor plan as a guide (above), interior elements such as wall surfaces, stairways, columns, and railings are now given vertical dimension using Adobe Illustrator's "nudge" keyboard feature (Command V>Arrow Keys) to move them upward in small increments. The proper vertical height of each object's uppermost line is determined by a vertical measurement scale used in the master perspective grid.
All of the common furnishing and interior elements that would ultimately be at the same elevation height (i.e. chair backs, chair arms, and seat bottoms) were linked together with Adobe Illustrator's "Group/Ungroup" feature so that they could be raised at the same time using Illustrator's keyboard nudge command. Commonly grouped elements such as tabletops or chair bottoms are color-coded so that they are easily distinguishable from each other.
The example below shows the linked furnishing elements (via Adobe Illustrator's "Group" command) in perspective view after insertion into the master perspective grid and before each separate element is moved to it's correct vertical position (via Illustrator's "Nudge" command.
After each furnishing element is moved to it's correct vertical position, there is a plan-view perspective "framework" to trace over. Each item must now be drawn or re-drawn to create the finished line art which will be exported into Photoshop. Things can get very confusing at this stage but the color-coding really helps make things more readable.
When possible, identical room details and furnishings are cloned by using the Adobe Illustrator "cloning/copying" feature. This is done by using Illustrator's "Move" tool (solid arrow in the Illustrator toolbar). Once the move tool is active, hold down the Command and Option keys while using the incremental Nudge (arrow) keys. You can also use the Command and Option keys and drag the copied object to its new location using your trackball, drawing tablet or mouse.
Technical Note: When you mouse-over an active object while holding down the Command and Option keys, the solid "Move" arrow will turn into a double arrow (black arrow and white arrow).
Now that all of the line work was complete, the vector file was converted to a rasterized Adobe Photoshop layered file. It was converted as a grey scale file to speed the exporting process, yet it still took 9 hours for a G4 to export the file. Samples of the final line art are shown below. The final Illustrator file had 22 individual layers.
Technical Note: There is a known software bug in Adobe Illustrator CS/10 and Adobe Illustrator CS2 that will not allow you to export a file to Photoshop that is larger than 28 inches/300 dpi. Because of this bug, you must boot to Mac OS9 (or earlier) so that you can use Adobe Illustrator 9 (or earlier) to do the exporting (very annoying).
In addition, the rasterizing/export function in Adobe Illustrator CS/CS2 creates very rough line quality with a noticeable stair-stepping effect when converting a vector file to a Photoshop raster file. The problem with rendering (rasterizing) line-work has nothing to do with document resolution - it is a problem with how the software "averages" (smoothes) the stair-step effect when rendering a line that is at a steep angle (ie. 5°, 85°, 95°, etc.) or a gradual arc. Even if you use a workaround of exporting to a higher resolution (say 600 dpi), then scale the line art back down to 350 dpi in Photoshop, it is still hopelessly inferior to the now-ancient Illustrator 9 which had the best exported line quality.
The example shown below is an approximation of the final scale (screen size) that most of the line work was done. Working at this scale, the "physical" size of the illustration would be 12 feet if it were done as a non-digital image. Given the time involved, many students ask why I chose not use a CAD drawing program to create an illustration such as this? If you continue to Page 2 of this tutorial "Adobe Photoshop Color Work" to find the answer.
Note: The following hardware and software was used in this tutorial: An Apple Mac Pro desktop computer, a Wacom Intuos 6x8 drawing tablet, Adobe Illustrator CS drawing software and a properly calibrated monitor.
High-Resolution Cruise Ship Samples
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