technical illustration

 

Adobe Illustrator Tutorial - Cutaway Technical Illustration

All of the initial line artwork was done in vector based Adobe Illustrator CS. Most of the final color work (Page 2 - Photoshop Tutorial) was done in Adobe Photoshop. The techniques used in this demonstration tutorial are applicable to any 3 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 the project. There was no photography or CAD reference to work from, only the paper blueprint you see below. In order to have the brochures completed by the time the ship went into service, the final illustration had to be finished in under two months.

 

The first step was to map out the physical space that the ship would occupy (below) by creating a perspective grid. By establishing a horizon line and vanishing points, an angle was developed that showed the maximum amount of features on the ship.

Technical Note: This type of technical illustration angle is generally referred to as a 3/4 perspective view. For more information on perspective drawing techniques used in mechanical drafting and architectural drawing, go to: 2 Point Perspective Drawing Tutorial.

 

The next step was to lay out the deck elevations, deck levels and cross section views using a pre-defined scale of measurements within the master perspective grid.

After the layout was complete, work began on the individual decks. Working from the blueprint (A), each deck had to be indivdually 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, they were distorted into the master perspective grid using Adobe Illustrator's "Free Transform" tool. Once distorted into the perspective grid, they provide an "in perspective" floor plan. Common objects and furnishings that are linked or grouped together are raised to their correct height. All vertical and 3 dimensional objects are then re-drawn using the distorted floor plans as a template.

Technical Note: Adobe Illustrator CS (or any other technical illustration 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 Student Tutorials page.

The next step was to decide where to cutaway both the outside of the ship and each individual deck surface to best show the important interior details in each public space.

Using the distorted floor plan (above) as a guide, interior elements such as wall surfaces, stairways, columns, and railings are now given vertical dimension using Adobe Illustrator's keyboard "nudge" feature. Vertical height 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.

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 verticle position, there is a perspective "framework" to trace over. Each item must now be drawn or re-drawn to create the finished line art.

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 it's new location using your trackball, drawing tablet or mouse.

technical illustration 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 Photshop 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). Additionally, 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 example shown below is an approximation of the scale that most of the line work was done at. At this scale, the "physical" size of the illustration would be 12 feet! Why not use a CAD drawing program to create an illustration such as this, you ask? Continue to Page 2 "Adobe Photoshop Color Work" to find the answer technical illustration

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