perspective question

[Adam]

Hey guys...This q may not even HAVE an answer, but how do you choose where to place your vanishing points for 3 point perspective? I remember how to work with them and all that, but my placement lately is ASS - very trial and error :( Do you have any rules of thumb and/or tips on where to put them? Bengal's art especially has me wondering - he does the coolest camera angles!

[Erik]

I'm not sure if Bengal uses vanishing points though... seems to me he just draws that stuff straight on to the paper :-/

I can't help you with the vanishing points except that it is often all too easy to have them on the paper, so they're really close to one another. The angle between the vanishing points would then be like say 30-45 degrees, where the human eye can see in a much larger arc. That makes stuff bend way to much. At least that's my view on the theory... but i admit i suck at perspective... :-(

Put the vanishing points way out off the paper! (helps to tape your paper to the table and use a string or something tied to a tack so the paper won't move and you don't need a really long - what's the english word for 'lineaal' ? - ehm. utensil to draw along)

Hope this helps.

[Fipse]

Ruler, the word was ruler, Erik ;).

Fipse

[Erik]

yeah... now i remember ;-) thnx

[saturnfive]

I'm not sure if this is true, but I read that horizontal (ie: 2 point perspective) vanishing points should be around 8 feet apart for a 'natural' looking view cone.

You can use string, long rulers, or there's a method with a compass to work them out on the paper. Easier to do them on a computer though, I think, either work the grid out in 2d and crop it after, or make a VERY rough 3d model of the principle simple cubes and cylinders: that way you can choose the exact camera angle and FOV that you want.

[Atomick]

Adam, the closer together your vanishing points are, the more extreme your "camera lens." Nothing pays off like experimentation, but the more naturalistic your scene, the farther apart them puppies need to be.

A couple of quick ideas for setting up perspective grids digitally, because it's a great way to experiment...

I often block out some basics unassisted in PS or Painter first. I then toss 'em into Illustrator, where I create my perspective lines. As saturnfive indicated, vanishing points often need to be way off your standard canvas, and doing them in Illustrator is a great way to work on an immense canvas without chewing up all yer RAM. When you've got the basic perspective lines down, bring 'em back into PS or Painter as a layer, via import or paste. (Because you can repeat/duplicate previous steps, Illustrator is great for replicating tons of perspectives lines for huge spaces with columns, etc.)

Photoshop is especially good at retaining image data beyond your canvas area (a feature from v5 called "Big Data"), so even after you plop 'em in, you can move 'em around freely. Or, alternatively, after PS v6 you can keep them as vector layers.

If you want to stick to Photoshop only, zoom out to where your image is tiny on the screen, and open up the window so you see that standard gray BG around your live canvas area. Now, drag some guides out from your rulers to where the vanishing points intersect, and use Photoshop's own vector line tool to create your perspective lines.

As a final suggestion, if you have access to even a simple 3D program, toss down some primitives (cubes are the best) and render out a still. Then, trace these perspective lines in PS or Illustrator, and watch where the vanishing points meet!

(Once I again I shall plug that useful, IMHO, "Perspective! For Comic Book Artists" book, you can get it on Amazon...remedial but really super-clear...)

FWIW,
-Atomick

[Adam]

cool, thanks for the advice guys - i'll see about that book. I am still wondering about the actual positions of the points - it makes sense that they should be far away, but where, i guess radially, should they be put? Maybe i'll try the 3D thing, that should probably help! Thanks again!

[ansonjew]

I'm no expert, but here's how I understand it...

The farther apart you place your two vanishing points the longer your "lens" is in the picture (telephoto). The closer you place them, the shorter the lens (fisheye).

Your question is essentially about how this relationship relates to the "framed area" of your image. As a general rule, the angle created by the intersection of the two lines eminating from your vanishing points should never be steeper than 90 degrees (or you will get a distorted "fisheye" effect). Therefore, you should place your vanishing points in such a way that any intersections with an angle steeper than 90 degrees fall OUTSIDE the active image area of your picture frame.

I hope that made sense. Anyways, I pondered that question for a long time myself, and finally found the answer in Andrew Loomis' "Successful Drawing" (page 76). Another highly recommended resource is John Montague's "Basic Perspective Drawing".

Hope that helps,

Anson

[davi]

i'll answer for bengal and let you know that he doesn't really do do true perspective and just guesses every well.

[Adam]

haha - yeah that doesn't surprise me about bengal - anson, thanks for the tips!! I will try that out tonight - I just checked, and my old perspective sutff aften has steeper than 90 angles on it - thanks again!