Author Topic: PER104: Orthogonal Cutouts  (Read 8716 times)

Mother Roshiya

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PER104: Orthogonal Cutouts
« on: June 19, 2015, 11:25:24 PM »
And welcome back! I trust you all have been practicing your one point perspective boxes and plane division techniques that were discussed in our last lessons? And you did the extra credit bit about the cutouts too? No? Go back and brush up on those really quick, I'll wait!

There you are! Now that you're a Plane Dividing Expert and can create cutout shapes on a facing plane in one point perspective, let me introduce you to your next step in becoming a perspective master:

How to Draw Orthogonal Cutout Shapes!

I know you must be biting at the bit to learn how to make those cutout shapes on the orthogonal depth planes by now, so let me introduce this technique by teaching you how to create the most common cutout shape you'll use: the cylinder.

Cylinders are used in columns, pens, table legs, cups, candles, bottles, tape dispensers, wheels, baskets~you name it! So you need to know how to make these things! And before you can make a cylinder, you first have to know...

How to Draw an Ellipse on a Plane

So let's jump in finally, shall we?

Step 1: Create a Plane
This may sound weird, but you first have to draw a square or rectangular plane of the height and width you want the ellipse to be before you can draw an ellipse in perspective:

Step 2: Divide the Plane
Create some guidelines by halving your plane both horizontally and vertically. Don't erase anything; we're going to need all of these lines.

Step 3: Draw the Ellipse
I'm going to be completely honest: ellipses are tricky to draw, so take your time on this. A 'perfect' ellipse touches the edge of the plane at the exact middle, and crosses the diagonals at the same relative location all the way around. Until you get a good feel for it and can freehand ellipses with confidence, or if you just feel the need for that extra technical precision, I suggest the following method:

Draw a curve that looks good from one middle line to another middle line

Then create a plane inside the plane that connects the diagonals

You can then use the corners of the inside plane as your guide points in creating a perfect ellipse

This technique is especially useful when you need to draw a line of identical cylindrical columns, but we'll delve more into that in a future lesson on shape placement relations. And now that you know how to make an ellipse, let's move onto making orthogonal cylinders!

Orthogonal Cylinders

Alright, enough talk! Let's make some cylinders!

Step 1: Draw your Horizon Line
Just like before, you need a horizon line before any perspective drawing can take place, to orient the viewer in the picture plane's world.

Step 2: Decide your height, width, and depth
And you do this by creating boxes, just like we did before:

Step 3: Divide your Front Orthogonal Plane
Just like we did for the ellipse above, we have to halve our orthogonal plane horizontally and vertically, so connect the corners of the plane and divide whichever direction is your parallel dividing line to your height or width lines first

Then line up the middle halving point with the vanishing point and draw the line to divide your plane in half along the orthogonal depth lines to complete your guidelines

Step 4: Draw the Ellipse
I chose to freehand my ellipses, but if you were to choose to use the rectangle technique for your guide points remember that any and ALL depth lines are to be extended to the vanishing point!

Step 5: Divide your Back Orthogonal Plane
Halve your plane horizontally and vertically, again remembering to extend your depth lines to the vanishing point!

Step 6: Extend your Guide Points
Now, it's true that we could just freehand the ellipses on the back plane, but we want them to match the ellipses on the front plane, so extend a line from where the front ellipse crosses over the diagonal guidelines on the front plane (this is really easy if you chose to do the inner plane guide technique) to where it touches the diagonal guideline on the back plane

Step 7: Draw your Back Ellipse
Using your extended guide points, draw your back ellipse.

Step 8: Draw your Curved Plane Edge
This "edge" isn't really an edge of course, seeing as a curved surface does not have a sudden change in direction that typically creates the sharp directional contrast associated with a "true" edge, but it is where the surface has curved back out of view and can no longer be seen. Seeing as our cylinder has straight sides, this "edge" is seen as straight. Find where your ellipses curve back in on themselves and connect them with a parallel line. Note: Whether it's a box or a cutout shape, if you do the shapes correctly, the edge lines that are parallel should be perfectly parallel. This is a good check to make sure your shapes are lined up correctly. If you have to tilt the edge line out of parallel, and you did not purposefully make one shape larger than the other, than your perspective or shape is off and you need to fix it.

Step 9: Identify your Seen Planes
For a cylinder your side seen plane is from your "edge" lines along the curve, plus~in this case~the top ellipse. Everything else is hidden.

Step 10: Clean Up
Erase your guidelines and you now have two orthogonal cylinders! Congratulations! You made it!

Go ahead and have fun with other sizes and shapes utilizing your guidelines and plane division prowess to make other orthogonal cutouts!

Just remember:

You start with a divided box

You create your shapes from it

And then you have your beautiful orthogonal cutouts!

As always, I look forward to hopefully seeing your masterpieces up on the WIP and Completed Works boards soon! If you're ready to continue your journey in mastering perspective, head over to PER105: Basic Complex Shapes to learn about the pyramid, cone and sphere!
« Last Edit: April 18, 2016, 06:30:53 PM by Mother Roshiya »