Relatively simple perspective question

[Steven Sweeney]

Limiting this response to the desired representation that was described

[Geary Wootten]

Originally Posted by Steven Sweeney

.........Voila, and it hardly even hurt.

......Qww - ya wanna bet? LOL.

Steven, Ken..et al,

Thanks for taking the time in doing this. In spite of my yucking it up, I actually learned some things today.

G. (reeling from left brain hook to right brain. )

[Steven Sweeney]

So, okay, I added the supporting illustrations above. That

[Allan Rahbek]

Steven

There is no "true" perspective, all of them are theoretical, fulfilling different needs. I try to avoid the use of linear perspective.

How did you place the two vanishing points ? Did you measured them to the right place or how ?

I think Ken will have troubles drawing in a small boat cabin. It is tempting to take a broader view when drawing in a small room. When seeing the drawing from a longer distance (than it was done) you will see distortions.

I will attach a drawing that, hopefully, will explain the perspective consequence of doing the wide angle view.

Allan

[Ken Smith]

Wow!

I'm suitably amazed. I never thought of myself as particularly left-brained, but this sure cinches it.

Last evening I actually was able to do the drawing using the plan perspective thing, and surprisingly (to me, anyway), it actually worked. Except that I made the horizon too low.

The reason I'm exploring this is that I'm doing a painting of 3 guys in the cockpit of a LCVP (a WWII landing craft). I have some 1/24 scale blueprints of the boat and a very poor plastic model and a bunch of photos (but of course none from the angle I need). I need to place these guys accurately to get the scale of the boat and a realistic view of the various angles.

After reading all this, and trying my own descriptive geometry session, I've decide to solve it this way:

I've taped out the layout of the cockpit full-size on the floor of my studio. I'm going to roughly mockup the sides and deck heights and so forth with some corrugated cardboard sheets, and then place the models where they belong, light them, sketch them, photograph them, and let that be that (and just be glad they weren't on an aircraft carrier!).

This has been a supremely informative discussion; I really appreciate all the info (and I actually sort of understand it, which I certainly didn't beforehand).

[Steven Sweeney]

How did you place the two vanishing points ? Did you measure them to the right place or how?

Allan,

You are astute to ask this question. In fact, in my quick sketch, I just located the vanishing points where it was convenient to do so. More correctly, one would have to establish a so-called "circle of view", the radius of which is the distance from the viewer to the image plane (or drawing). From any point, then, on that circle, the vanishing points would be 90 degrees apart (using the point on the circle as the vertex of that angle.) This gives you an infinite number of available perspectives, though a relatively small number of them will produce aesthetically pleasing results, which for our purposes here is the primary consideration.

A caveat, that this is the procedure for the cubic polyhedron. Other forms require modification of this approach.

All of which is why I suggested that Ken focus on what he could see, with an eye to aesthetic considerations, rather than worry about precision in perspective.

[Allan Rahbek]

Hi, I just stumbled over this old tread and thought that I should try to make my point less brief by adding a practical example to show how the viewpoint, and angle of the view, affects the perspective in the final painting.
As you see, on the left illustration, the angle of view is about 75 degrees out of the full circle of 360 degrees. To project the correct drawing one would have to straiten out the curve before projecting the lines, but I cheated.

[Claudemir Bonfim]

Hi there,

Nice thread!

If anybody wants, I can email the pages in a larger size.

All the best.

[Claudemir Bonfim]

These are all from the book "Successful Drawing" by Andrew Loomis.

I've got many more pages about it.

[Claudemir Bonfim]

One might ask: "Why should I study about it? I paint what I see!"
First of all, painting is 90 % drawing.
Second of all, most painters paint what they "think" they see and not what the actually see.
Last of all, sometimes you need to paint a posthumous portrait, and in that case, the model cannot sit for you, so you have to use these rules to make a better job. Sometimes the lighting in a photograph is horrible, but you liked the pose, so, you can change the values, lighting, etc, if you master perspective.

Hope it helps.