Wall Illusion: Easy Forced-Perspective Wall Art (Without Using a Projector)

Overview:

Using only a cheap digital camera, some masking tape, and Illustration or Photo-Editing software, you can make some amazingly-handsome Trompe-l'oeil/Forced Perspective wall-art (yes... very much like that awesome parking garage that everyone on earth forwarded you). Your friends and neighbors will be astounded by your cleverness.

Viewed from the proper angle, the illusion of a 2-dimensional "flat" image is presented, but viewed from the side you will see the gross distortions that make the "proper" angle possible.
Note of Thanks: This Instructable was influenced greatly by--and wouldn't have been possible without--the help I received from this thread on AskMetaFilter. There are some smart and creative folks there who can really help a guy out with a project. (If you can wade through the questions about recipes, pets, or relationships, you'll find some absolute gems.) Thanks guys; awesome input.

Step 1: Tools and Materials Required

Required:

• a Blank wall meeting at a corner
• a Vector or very-high-resolution raster image or logo(here's one source I like... there are hundreds more)
• a Digital Camera - I used a cheap, old 6 Mp Canon, but I suspect you could get good results with even a 3 Mp camera. Much lower than that, and you might have problems.
• Drawing or Photo Editing Software - (I used Illustrator and Photoshop CS2, and provide instructions for these packages, but there are several other Free and Non-Free software packages that would work just as well).
• a Measuring Device
• Masking Tape(Must be a visibly different color than your wall).
• a Printer or other output device. - You can Rasterbate your image, or have it done fairly inexpensively at a print shop. I'm not big on Kinkos, but they can do it pretty cheap -- (<$5)
• a Utility or X-Acto knife

Optional:

• a Spirit Level
• a Second Color of Masking Tape
• a ladder or step-stool
• a Second Set of Hands(makes the ceiling bit a lot easier... but far from a requirement).
• a Protractor or Combination Square
• Sandpaper(for surface prep)
• a Vinyl Plotter(or make a friend in a sign shop. Completely optional -- looks great printed, too.)
• Cleaning Solvents(for surface prep). I used a mild soap and then rubbing alcohol
  

Step 2: Pick Your Wall, Pick Your Image

SELECT YOUR WALL:
You want to pick a place where two (or preferably three) surfaces meet. I picked the dreary and ugly corner pictured below. Some considerations to take into account when picking your wall:

• Does it have a clear line of sight to where you want the illusion "focused"?(Even the coolest image in the world isn't going to "pop" unless you have a good place to view it from. Pick a place that's far enough away [4m+] from where you'll be viewing it.)
• Does it have enough room for the image?(the most appealing illusions are going to be rather LARGE... the bigger the better. Does the wall have enough room to accommodate the scale of the image?)
• Will mounting the image be a problem?(Is the wall rough or stippled, or will it present any impediments to the specific mounting-method you are going to employ? How high up is it? Do you have a ladder?)

SELECT YOUR IMAGE:
I worked with a single-color image. This makes printing costs quite a bit more reasonable and the contrast makes it "pop" more. I bet some cool effects could be accomplished by using images other than linework... but it's going to make it more complicated. Try to limit yourself to fewer (ideally "one") color to save some headache... (or, hell, go all-out... I'd be excited to see what you can come up with if you pull it off). Some considerations to take into account when picking your image:

• Can you get it in vector format?(Not a requirement for the project, but it makes things quite a bit easier.)
• If you're not working with Vector, is the image's resolution sufficient to blow it up to the size you want? (Not going to go too far into this in this instructable, but there's probably an internet forum out there who could help you if you're unsure about what constitutes "big enough".) It's to your tastes and your quality-standards, ultimately. I wouldn't make something of anything close to this size without a 2000px raster image, minimum. Your mileage may vary. Additionally: There are many ways to vectorize raster graphics... Poke around for an instructable if you're interested. Some methods produce great results, some not-so-great; and some are easier than others.
• Will this image look cool in forced perspective?(Personally, I like how geometric images come together in forced perspective, but I've seen some awesome organic shapes, as well. Typography would look nice; high-contrast looks nice... Give some thought to finding the perfect image; there's tons of 'em out there).

I ended up going with the following logo. I found it on Wikipedia where it is available as an SVG (vector) file on the image's download page. It's also public-domain, which I'm very thankful for... I wouldn't want to be the target of Abahlali BaseMjondolo's high-powered ivy-league lawyers.

Step 3: Where Will You "Focus" the Illusion?

[The schematic above is overly-detailed and is presented here for illustrative purposes only. You need not make it -- or even be able to read it -- to complete this instructable.]

Hopefully, your finished wall-hanging is going to look interesting from any angle, but there's only gonna be one spot in the entire room -- and by this I mean one spot on both the X/Y axis, AND the Z (height from floor) axis -- where this image "pops" and appears flat. It's important to give some thought to where you want the "viewing spot" to be.

At the very least, pick a place where people's eyes can physically BE... not many people are going to be standing on top of your refrigerator, so why make the focus there? Try to pick a place where people's eyes are likely to linger. Maybe at "seated-in-a-chair height" in the spot where guests are likely to be seated? Maybe at "average-standing-human-eye height" from where guests pause immediately after closing your front door behind them? Pick a place that suits your specific application and one that's going to look killer to you and the people likely to be viewing it.

Step 4: Measure and Tape Your Walls

OVERVIEW:
In this step we're going to measure out three rectangles of known sizes, and make rectangles of masking tape of exactly these sizes -- one on each of our three surfaces. It is important to note that the purpose of making these tape rectangles is to provide contrast for the photo you will shortly be taking. That being said, it is important to select a tape color that provides good visual contrast with your wall.

SELECT SIZE OF RECTANGLES:
The size of the rectangles you select is, ultimately, an arbitrary decision -- but it will be influenced by:

• Size of your printer/output device(I was going to output to 24" wide vinyl... so I made my rectangles just a shade under 24")
• Size and proportions of your image/logo(My image was a circle. So my 3 rectangles are roughly the same size. If your logo has an eccentric shape, or is markedly off-center, you might want to make one/some of the rectangles larger or smaller.)

For my project, I selected rectangles of 22" x 22", 22" x 24", and 18" x 18". Yours will probably be different. I chose slightly differing dimensions so that they would be visually distinct from one another (so that the edges would be staggered). This helped out quite a bit, and I would recommend doing this.

MEASURE AND MARK THE RECTANGLES ON THE WALL:
Use a pencil and measure out the rectangles by marking the correct distance from each wall. If you have a combination square or a spirit level, these might help to double-check your measurements. I'm not saying that you have to have it exactly right down to the millimeter, but the more accurate you are at this stage the more accurate the transformation will be. So, why not spend a little extra time on this step and get it as close as you can?

TAPE THE PERIMETER OF EACH RECTANGLE:
You're looking to make a "box" of masking tape for each of the three rectangles. Look at the picture of the finished boxes to help you out if you're having a hard time visualizing it.

Remember: Keep those taped lines level/plumb and keep your angles square! I've worked for years as a signmaker, so my visual sense of "level" is pretty (preternaturally) accurate... if you're having doubts about your ability to do it visually, it might be time to whip out the spirit level/combo square again at this point.

Lastly: take your X-Acto knife and trim away the excess tape leaving something close to perfectly square corners.

PROVIDE A CONTRASTING COLOR WHERE THE BLUE RECTANGLES TOUCH ONE-ANOTHER:
I mentioned that we're gonna be photographing this, right? So, unless you want to drive yourself crazy staring at pixels in your image-editor and trying to decide where one blue shape stops and the next one begins, we should provide a visual "break" between the two boxes.

I used colored electricians tape. In the final analysis, I wouldn't recommend this. The tape was fussy and difficult to work with. If you have an alternate color of masking tape, use that to define the edges. Or use a thin bead of paint, or a marker, or stickers, or whatever you'd like, but in summary:

Wherever one blue rectangle touches another blue rectangle on a different wall, provide a high-contrast visual break between the two.

Step 5: Your Taped Wall Should Now Look Something Like This

This is something like what you should be seeing at this point. Focus less on "making it look exactly like this" and more on "making it do the same thing." Your version doesn't have to be blue, be outlined boxes, be the same size, be as high-up... none of that. The only things that matter are that you have rectangles of known size that have crisp edges that contrast from the wall, and are visually distinct from each other.

Clarifying note about the picture:The "crosshair" pattern I put in the center of each one is not at all necessary. I did it because I thought it might be helpful. It was of no help or hindrance. I'd advise omitting them just to save yourself the hassle.

Step 6: Photograph the Taped Wall From the EXACT Spot You Picked to Be the Illusion's "Focus"

This Step Could Not Be More Critical:

Photograph your recently-taped wall. You should take great care to remember a couple of things:

• PUT THE CAMERA LENS WHERE THE VIEWERS' EYES WILL BE -- Not "a little to the left", not "pretty close to", and definitely not "a couple inches above or below". We're already dealing with some distortion from the wide-angle lens... but that's not all that destructive, all-told. Now, if you cock-up this step and go for "roundabouts" where the viewers eyes are; that will hurt and possibly ruin the final effect. Pardon my shouting, but it's just that essential: IF YOU ARE IN THE "VIEWING POSITION" AND YOU ARE HOLDING THE CAMERA IN FRONT OF YOUR FACE, THEN THE LENS IS NOT WHERE THE VIEWERS' EYES WILL BE.
• Keep the taped rectangles in the center of the frame, and keep it as close to vertical as possible -- Using a point-and-shoot camera with a wide-angle lens means distortion creeps into consideration. There's less distortion in the middle of the lens. We're going to be rotating the picture in our image editing program, but try to keep it vertical, just so you have less to rotate.
• Take a sharp picture -- I'm no kind of "good photographer", but this particular project doesn't really require one. We want a SHARP, contrast-y picture with no blurring. How do we do this? I'm sure a more skilled photographer could give better recommendations (feel free to make suggestions), but I just lit the hell out of it, kept a very steady hand, and shot on ISO 400. Remember: a sharper image at this stage means less headache and guesswork in your image editor.

Step 7: Set Up the Photo Using Drawing/Image Editing Software

ROTATE IMAGE TO VERTICAL, AND SHARPEN, IF NECESSARY:
Once your image is in your chosen software package, rotate the photo so that the vertical edge between the two wall squares is truly vertical. You can use a guideline as a reference and rotate it by hand, or any other method that suits you. In Photoshop you can use the "Ruler" tool to trace over the edge and then go to Image>Rotate Canvas>Arbitrary. The correct rotation value should already be entered in.

Feel free to sharpen the image using your preferred method. I'm not even going to open the can of worms that is "how best to sharpen images". Your image might not need it at all. Photoshop's (much maligned) "Sharpen" or "Sharpen More" filters might be useful in this instance for the first time in Photoshop history.

INSERT YOUR LOGO/ARTWORK INTO THE IMAGE, AND RESIZE IT SO THAT IT JUST FITS WITHIN THE OUTSIDE BORDERS OF THE THREE RECTANGLES:
Throw your artwork into the photo. Scale it so that it's a good fit for the outside borders of the rectangles. Take a look at this image to familiarize yourself.

Step 8: Outline the Taped Boxes in Your Preferred Software

Remember how I was real big on "Creating Contrast Between the Boxes"? Here's where it pays off. Create a box around each of the 3 individual boxes in your software package. Use a different color for each to keep 'em distinct and organized.

Step 9: Create "Cut" Lines Along the Edges Where Walls Meet

You're going to make what will become "Cut" lines along each of the edges... in this case radiating out from the center like spokes on a wheel.

Step 10: Split Your Artwork Into Three Pieces Along Cutlines

I'm afraid that I can't really make this into a Photoshop/Illustrator tutorial without watering it down or going off-topic too much, so I'll not go much farther than telling what needs to be done and suggesting a way to do it. There are any number of PS/ILL tutorials on the web that would do a far, far better job of "bringing someone up to speed" than I could. That said, here are some back-of-the-napkin suggestions for how this would play out.

There are hundreds of ways to do this in each program... the following examples are just one of many.

ILLUSTRATOR:
Put the cutlines and the Logo/Artwork on the same layer, with the cutlines on top. Select the cutlines and then Object>Path>Divide Objects Below. In addition to cutting along the "seams", this will also cut each panel into two parts (meaning we will want to then rejoin them). Rejoin them by selecting the two parts and Alt+Clicking on Pathfinder's "Add to Shape Area".

PHOTOSHOP:
Ctrl+click on the layer containing the outline of a specific box to select the area of that box. Then select the layer containing the logo/artwork. Copy, and paste to new layer. Repeat for the other two boxes.

Again... I'm sure there are many better ways to do this. These are suggestions only. I was trying to keep it simple so as to make it accessible to the most people.

Step 11: Group Each Wedge With Its Corresponding Outline Box

Step 12: Create Boxes With ACTUAL Dimensions in Your Software of Choice

If this has you confused, please don't be. It's simpler than it sounds. Here is what we're doing, conceptually:

We're making a box of the "real" dimensions. By "real" dimensions I mean: Remember when you measured and taped that box on the wall? That's what we just made in Illustrator. In my example, the box was W22" x H24".

Once we've created this box, we'll insert the traced boundary box and the "slice" of the artwork that we created in the last step.

In the next step we will transform it to the dimensions of the "real" rectangle.

Step 13: Transform/Distort Traced Rectangle to Match "Real" Rectangle

Simple as that. The tools you're looking for are "Free Transform" in Photoshop, or "Free Distort"/"Free Transform" in Illustrator.

Make the "traced" parallelogram match up with the "real-dimensions rectangle".

Step 14: Distort All Three Panels to Match Their "Real" Rectangles

You'll end up with some funky shapes. Here is how my three shapes ended up:

Step 15: Print a "Mock-up", (or Print the Real-Deal)

I took these three shapes and had 'em printed off as a mock-up for the vinyl I was planning on cutting. If your end-product is going to be printed, then I guess this is your final step. You'll want to do a more attractive and subtle job of taping/mounting, to be sure.

Step 16: Prep Your Walls for Mounting

You're already done if your goal was to print... but if you're going to use vinyl, you've got a tricky install ahead of you.

If you've never laid vinyl before, this is a potentially risky project to learn on, and I wouldn't advise it. If you've done it before (or are just feeling adventurous) a sign shop would probably charge you $30-$50 for this cut vinyl. (It'd only COST them around $3 [actually, closer to $6] of course... so you have a lot of room to haggle).

You'll want to prep your walls with a mild soap, and then use some rubbing alcohol as a degreaser so that the vinyl will stick better... but if your ceiling is anything like mine, you have a bigger problem: Those goddamn bumpy textured-ceiling paint nubs.

Some course-grit sandpaper will take care of it... but it is a miserable, horrible job. I hate sanding, period, even without sanding crumbly, dusty material directly over my head.

Solution:

Con someone else into doing the job. Invite someone over under utterly false (and seemingly fun) pretenses and spring it on them before they realize how miserable the job is. For bonus points tell her she should dress nice.

Step 17: Apply Vinyl and Finish Up

I mentioned in an earlier step that this is probably not the project with which you'll want to learn vinyl application. The skill of applying vinyl comes in handy for a range of art-related and fabrication-related tasks, and by itself is not altogether that complicated -- it's just sticking a sticker on something, after all -- it's a skill that you can absolutely pick up quickly... but I'd start slower and build up to something like this. The three surfaces (esp. the ceiling), small fault-tolerances in mating the edges, and the cramped quarters make an expensive mistake very likely for the first-timer.

I hope I haven't scared you off from trying it sometime, though... The moderate difficulty in laying vinyl under the constraints imposed by this project is the exception, not the rule. If you're interested, there are Instructables that cover vinyl install. Here's one, for instance.

Step 18: Summary, and the Road Ahead...

This was a very satisfying project for me, personally... I'll be taking the things I learned from this project, and applying them to many others.

I'm currently kicking around in my head a way to use this method to attack a project that uses quite a few more surfaces and several more "planes" of interaction. Here's a mock-up of the next forced-perspective project. I'll let you know how it goes, and post an Instructable if I find a method that works well.

I'd love to help you with your forced-perspective wall-art... so feel free to ask any questions you may have, or to ask for clarification on any sections I may have left unclear. Many thanks, and good luck on this and all your other projects. - jjijj