Perspective - need help in building up an object

# Thread: Perspective - need help in building up an object

1. ## Perspective - need help in building up an object

hi everyone,

for most of the time I never really needed to really construct anything from scratch in perspectice. But now I finally wanted to really do it. ^^

Surprisingly I got stuck really early.

I made a sketch first and then decided to pick it for a construction practice.
A Chess piece on the board.

i started with the base line and tried to build up a 2dimensional cut in space that goes through the middle of the statue.
But when I wanted to construct the depth I got stuck. how do I actually know how far I have to draw a line so that it forms an actual sqared shape and not any kind of rectangular?

Thanks for help.
I already looked up through quite some tutorials but most of them cover this part just as "and then you add depth" or something like that.

2. I have no idea about perspective but common sense tells me that to make the shape squared off, I'd have to either measure the vertical length line and repeat it but also remove some of it for foreshortening, or use my eye to judge how far to go with it before it looks like an elongated rectangle rather than a squared off shape which is what you're going for.

No idea if that helps but I couldnt leave you with zero replies.

3. first of all, make the canvas big enough so you can see the vanishing points. all's it has to be is white. then when the drawing is done you can crop it and just worry about the painting aspect.

4. I hope I understand your question. The method that I’m using can be found in much more detail in Loomis’ “Successful Drawing” book. You’re going to have to know what the actual measurements of the object are in order to get what you want, and you may actually find it more helpful to draw a side view instead of a top view. I only used a top view because of the simplicity. Anyway, I hope this little sketch is helpful.

(I hope the image loads. My internet connection has been awful today.)

5. Thanks everyone.
I will check on loomis again when I find some time.

For now I did what I usually do: Guessing

Si I tried to guess how wide the rectangular shapes have to be to look somewhat like a squared shape in perspective.

After that it felt more easy though wonky, as I build it all up on a guessed shape.

6. Have you tried modeling it in sketch up or some other 3d package, that could help you work things out in your head it does me. I am not suggesting painting over a model or anything but sometimes when struggling with perspective issues it helps.

Just a thought mate, if you want I could construct one in "Bryce", thats the package I play with more than most shouldnt take long, do you ant me to? Y/ N

7. If it doesnt take you too much time that would be nice.

Though I know about 3d support (I would usually use them for interior stuff or trying out arrangements) I wanted to understand how I can do this myself. Most of it works and I understand how to construct stuff, except the part where I have to add the depth without guessing if it is squared or not.

8. ok I will post it up tonight mate watch this post as they say!!

you can always print it and work the vanishing points etc back from it and otherwise work out how it was constructed

9. If you like now have the mid-line of the piece and the vanishing points you can use diagonals and see that they cross mid-line sections at same place to get the depth equal at both sides of the mid-line.

Right?

I'm kind of confused, and not quite sure what you asking about. But thought this might be it.

Last edited by w176; March 12th, 2012 at 05:45 AM.

10. Yeah, guys, guessing it is easy when you have a lot of skill with perspective already or don't need too much precision. But what if you have to actually construct the perspective?

What you want is the "architect's method" of making perspective from a plan. That's the simplest way to construct a square in perspective from any arbitrary point.

Generally, when you have already sketched the angles out, matching an elevation plan to the picture can be a real pain. So you might want to download Sketchup or Blender and whip up a quick scene in 3D. It would be far easier to match to the sketch since you won't have to redraw anything.

But in this case, you can try the architect's method, since you can guess the angle of the chessman pretty well in this case - from its position on the chequer board.

11. Starting with a cross section and making round forms from polygons works fine in a 3D modeling program, not so much working by hand.
Plus, your cross section is totally off to begin with.
First construct the box that will enclose your form.
Then, inside the box, construct the cylinder that will enclose your form.
(Although, on second thought, in this case the overall bounding shape is more likely to be a cone than a cylinder.)
If you don't know how to do those things accurately, then tackling a complex, multi-component form like a chess piece is a fool's errand.

12. ## The Following User Says Thank You to Elwell For This Useful Post:

13. @Elwell: Sadly there have never been any perspective classes in my school so I tried to learn it together with everything else on my own.

Thanks for the different approach. I thought starting from a "half cut" would be a good idea but maybe that was not the best choice.
I will start over with your idea and see how much it changes.

14. You've set yourself an especially difficult problem because your chess piece is a tapering form. Lying on its side, none of its three major axes will correspond to the ground plane. The way you have it set up, its long axis is parallel to the ground (and its base is perpendicular), but since the top of the piece is narrower than the bottom, that means it's floating above the surface, not resting on it.
Perspective is hard. If you're teaching yourself, you need to start much more simply.

15. Ok so I'm early!!

You seemed stuck and so I thought I had better get a shift on, I have saved the construction as well so if you want anything moving or whatever just tell me ok!?

I hope these help you out, I did two one with a rather rushed chessboard and one without.

Ok bud all the best with the image.

16. Thanks, nice to see it. I would have used a real chess piece as a ref, if I would only own one. ^^

I will construct some more simple pieces to practice this more. ^^
Like I said, I dont have a problem with using a 3d programm, but I want to be able to at least sketch it in the right way.

Starting with a box and then modelling it isnt as easy as it sounds though.
I guess I just need some more practice and experience to be able to say how far apart the VPs have to be.
Putting them anywhere is no problem, but making it an rectangular piece is a little guessing. Or you need to use that Architect transfer method.

17. There's probably a few free chess 3d chess pieces around the internet, check if you can find any.

18.

19. Sigh!

Looks like I fell short of the mark again!! however if my quck 3d job is garbage! dont worry, I have a chess set around here somewhere and a camera. Its an old world approach but I am prepared to help you out if you want mate.
I rather think it will help to visualise exactly what you want before you do a complicated set of perspective lines and vanishing points, just my thougts is all buddy.
just sketch roughly what you want and i will snap some pics for you if you want, its no problem matey.

all the best with it whatever you decide.

20. Hello Vaejoun,

Here is a way to figure out accurate dimensions in perspective by hand.

You'll need to make a plan and section.

1. Place the plan at the top of the page and mark a Station Point at the bottom of the page. (for now, imagine the screen or paper you are drawing on is an aerial view and you are looking down on it, the Station point is where the viewer would be standing in the scene and the plan is placed like it would be in the scene looking down on it - at whatever rotation and distance from the Station Point (viewer).

2. Ddraw a horizontal line called the Picture Plane touching the bottom most corner of the plan. The picture plane can be imagined in space as a piece of glass or a screen that could capture the image of the object in perspective that you're going to draw.

3. Draw a vertical line from the bottom most corner of the plan (where the picture plane is intersecting the plan) down to the station point. This line shows the distance from plan to station point.

4. Next we locate the vanishing points on the picture plane (note: these are not the Vanishing Points used for drawing the perspective, we'll get their). From the station point, draw a line up and to the right that is parallel with the right side line of the plan. Make this line intersect the picture plane. Now draw another line from the station point up and to the left that is parallel with the plans left side line and intersect the picture plane.

5. Place the Horizon Line below the picture plane where you'd like.

6. Now we locate the Vanishing Points on the horizon line by drawing vertical lines that start at the V.P.'s on the picture plane and go straight down the page intersecting the horizon line. Make a dot, these are the locations of the Vanishing Points on the horizon line you'll use to draw the perspective with.

7. Place your elevation drawing to the right or left of the station point, move it over far enough so it's not in the way of the soon to be drawn perspective image. Notice in the drawing how it's above the station point. Draw a line at the bottom of the elevation called the Ground Line (also called a base line) and extend it across the page. This line is the ground in elevation and also will give us the beginning of our perspective drawing.

8. Draw a horizontal line from the top of the elevation across the page. Notice how it intersects the vertical line we drew earlier that connects the station point with the corner of the plan.

Now the drawing has its layout and we can draw the perspective
accurately. saucy.

Note: in the perspective drawing to come, the corner that will be closests to us is called the true height corner. This line is the only line in perspective that has an accurate measurement.

9. Darken in the true height corner of the perspective drawing. This line is already plotted in the layout - the ground line and top of elevation line mark the start and end of this line where they intersect the vertical line drawn from the station point.

10. Connect lines from the true height corner line with the V.P.'s.

Now we can figure out the accurate dimensions of both sides of the object in perspective!

11. Draw a line that starts at the station point and interstects the outer most right-hand corner of the plan. Draw another line starting at the station point and intersect the outer most left-hand corner of the plan. I think this is called the view cone. make dots where those drawn lines intersect the picture plane. Draw vertical lines starting at those points down through your perspective lines. These vertical lines intersecting your perspective lines are the outer edges of the object. Now you've found the accurate thickness of the object in perspective.

12. Finish the perspective by drawing lines from the corners of the object to there respective V.P.'s.

or, use sketchup.

Last edited by Derra; March 14th, 2012 at 07:28 AM.

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22. Sorry to hijack your thread, Vaejoun, but thats an excellent explanation, Derra, and it makes a lot of sense when you put it like that. I got a lot from it and will be storing it in my memory banks for when I start working on the perspective beast.

Slightly off topic.

As for working these things out by actually drawing them being old world? I don't know about that but I figure if I want to learn something related to art, I should learn to draw it by hand. So in that regard, I'm with Vaejoun.

23. sorry lightship beat me to it but i made a quick sketch from your cross section, might help..

24. Yep I tried to help out but the model I made wasn't fit for purpose it seems and he wants to work it out by proper means with pen and paper.
Which I think is a good idea, if you dont get how to put it together then practice is the thing. I got too reliant on 3d package to do my perspective thinking for me and went back to the books to get my head round it again after a guy in here asked what was wrong with his image. It was a city in an underground sewer system and i couldn't remember how to show him how to construct an arch in perspective, sad but true.

oh well enough rambling I hope the image goes well "Vaejoun" and if you do want me to do anything else feel free to shout, all the best matey.

25. Here's an old school book that breaks down perspective really well. Straight nuts and bolts, and you don't have to dedicate several weeks to the book to get through it.

http://www.amazon.com/Perspective-Dr.../dp/B000SKM5U0

26. That looks like a good book but it's in the US. I found this one by the same guy, I think, which has more pages but costs roughly the same in UK money. Not sure if it's the same book, just a later edition, but it also looks pretty good -

http://www.amazon.co.uk/Perspective-...1913268&sr=8-1

I might go ahead and add it to my wish list for later - I really need to learn this stuff properly instead of relying on decades old school lessons and common sense.

Thanks for posting a link, Derra.

(I hope Vaejoun doesn't mind me taking over his thread...)

27. I guess it comes down to want you personally want to do.
Some people love learning perspective, and using their 'analogue' techniques is part of the joy and challenge of work.

Escher for example is one of the most righteous artists I can think of and did all his astonishing plays on perspective using those techniques.

If thats for you, by all means go ahead and learn the science of perspective.

if on the other hand you just want a perfectly perspective'd chesspiece for use in an image, then save time and do it in 3D so you can spend more time concentrating on the other aspects of the image; composition, story, texture, etc.

Different tools for different jobs etc etc