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Guest kaiza

Tutorial - Perspective Grid For Sketching

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Guest kaiza

If you’re trying to do a drawing with nice perspective, chances are the vanishing points are somewhere off your page. This technique is a good way to make sure all of your line work still maintains the right perspective.


For all of you digital sketchers, I’m not sure if this will help you at all (you may have a better system), but I imagine you can always use the final result as an image on the bottom layer with reduced opacity.


First things first, open up Illustrator and start a document that is the same size and orientation as the sketchpad you work with - for me that’s landscape A3.


The great thing about Illustrator is that it has the area around the artboard. The artboard is the area you work in, in this case its the A3 rectangle you can see in the middle. Plenty of space for us to set up our vanishing points outside the page!




Now we need to make two lines - I use the line tool but the pen tool is fine, just make sure they are two separate lines.


Match the points at one end - this will be one of your vanishing points. To help, try turning on smart guides (view -> smart guides or ctrl+U), and use the direct selection tool (the white one, shortcut A). Select both lines and group them (ctrl+G) so its easy to select and move them around.




Here’s the tricky bit: go to object -> blend -> blend options and set spacing to specified steps with the steps something around 20.




Now select the group of lines and go to object -> blend -> make (alt+ctrl+B ). If at any point you want to change the number of lines, select the group and go back to the blend options dialog box.




With the specified steps option the blend tool adds lines between two (or more) paths, even curved ones with more than one point. It will also blend between paths with different stroke weights. A very handy tool!


Here we’re just using it to add evenly spaced grid lines. The advantage of the blend tool is that we can now move our lines around to get the perspective we’re after and the extra lines will change to suit. I’m not going to go into the theory of perspective drawing, partly because its important that you play around and see what works for you, and partly because I can’t remember very much of it ;).


Anyway, just drag the object around (selection tool, shortcut V) until you think you’ve got a decent spot for your vanishing point (chances are it’ll change once you’ve got the other two in place). Then using the direct selection tool, click on the end points of the original two lines and drag them so that all of the lines stretch across the whole page.




Be careful about how you drag the lines around – if they are exactly 90° they can start playing up, likewise if you reverse the line it will twist the blended lines around (it’s a nice effect but not what we’re after).


All you need to do now is copy+paste the blended object and position it in the right spot. Use the direct selection tool to drag the points around to the new positions across the other side of the page. I’ve used a guide to make sure the vanishing points are level, if they aren’t your objects will look rotated – it may be an effect your after, so as I said, play around.




The great thing about this technique is you can do proper three-point perspective! It helps if you place the vanishing point along an imaginary (or real, if you use a guide) line extending through the middle of the page, and place it a fair distance from the page, so as to not look too “dramatic”.




To tidy it all up I drew a rectangle along the page borders (it helps if you’ve still got smart guides on), and used that as a clipping mask over the blend objects (select everything and right-click -> make clipping mask. Make sure that the rectangle is the top object in your layers palette). I also reduced the stroke weight of the lines from 2 to 0.5. This is a personal preference and depends on what your printer can print and how thick you want the lines behind your page (thicker lines are easier to see).




To print, it helps if you have an A3 printer (I’m going to run some of these off on the uni printer), but you can also do it on an A4 home printer. I add a vertical (hold the shift key when you draw it) 2pt “reference” line slightly to the left of the middle of the page, and then go to file -> print. Make sure the file is oriented correctly - you want the reference line vertical and just visible on the right of the print area (Illustrator will probably orient the file on its side) once this is done hit print. Then go back to the print dialog box and move the document so the reference line is on the left.


Once you’ve got both halves, cut straight down the reference lines and apply some tape to the back and you’ve got a nearly-A3 page.




OK, so how do you use it? Stick it under your page and use the lines as a guide. Because this is all perspective it’s difficult to rely on it as a proper grid, so try to avoid sketching only on the lines. If you want to draw between the lines, just approximate where the line should be. Here’s a quick example I did in Illustrator to show what I mean. I just fudged the ellipses, using the grid as a guide to how “fat” and “rotated” they need to be.




Just some notes: PLAY AROUND! Don’t follow my example to the letter. Experiment and see what happens when you muck around with the placement of the vanishing points. For example, if you want to draw a building like you’re looking up at it, you’ll need to move the bottom vanishing point above the page. The further apart the vanishing lines, the less perspective there will be.


Check out yo1’s tutorial on how to choose the appropriate perspective here


The file might take a little while to print straight from Illustrator – it depends on your printer and on your computer – it might even seem that Illustrator has crashed – just be patient, go and make yourself a cup of coffee or something ;). Alternatively and this applies to people wanting to use this in their digital sketches, save the file as an image. Deselect everything and go to object -> crop area -> make. You should see crop marks appear at the corners of the artboard. Now go to file -> export and I like to use PNG – its great for line work because of the way it compresses the files – you don’t end up with artifacts like in jpegs. I set the resolution at Medium, but use what you like, set the background colour to white, and make sure anti-alias and interlaced are unchecked. Save the file and print from Photoshop if necessary.


Here is an A3 (at 150dpi) sized PNG image of the grid.




Chances are you will need different guides for different drawings – otherwise they may all start looking the same. Keep them and see if you can label them to describe the sort of look they achieve.


Happy drawing!

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Guest kaiza

For those who are interested, here is the tutorial Illustrator file in a zip at the bottom of the post.


(the other image isn't mine - it's a bug in the forum software)



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Guest dc_dizzle

Dude not bad...not bad at all...Il definitely be making my own templates like this and be printing copies off...more than one cos im bound to lose em like a good industrial design uni student. You know if only u were half as creative with the girls as u are with solidworks and the adobe programs u wud be a pimp!...a pimp u hear me!....*ahem* once again good job...LOL i still gotta get into those tutorials that u gave me for adobe and solidworks...

we got 6weeks holidays left...plenty of time ;-)


lata dude

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The problem with those grids is that they only offer guidance on direction, but you can't measure any distances with them because the resulting grids aren't evenly spaced. For this you need to manually create grids...

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Guest kaiza

yeah, its definitely something to be wary of


after doing this tutorial i looked into ways of producing correctly spaced perspective grids, but the problem is that the grid is only useful in a single plane, otherwise you need to add extra construction lines and then everything starts getting messy...


you can get a decent one by doing a 2d grid and using Illustrators 3D feature to rotate it around, but it doesn't give you as much control over where the vanishing points go, and its difficult to get the third vanishing point.


i also looked at mathematical ways of creating the grid, but most of the relevant material is for computer games and is way above my head. all i could figure out is that evenly spaced lines receed in proportion to a trigonometric function (tan i think). if i find a way to accuratly draw or import mathematical curves in illustrator i might have a second crack at this.

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Guest kaiza

Just gonna give this a quick bump - found the old images which I had previously had uploaded on my old webspace - now uploaded through the forums.

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