Industrial design hand-drawn, hand to teach you step by step to draw a good ellipse.
Camera painting is not good, it looks old and strange, there are students say telescope is so difficult to draw, in fact, in addition to the root of the problem of perspective, a large part of the reason is that the ellipse is not well drawn, so how can we draw the ellipse well?
Dissecting the ellipse
When looking at a circle from a certain angle, we see an ellipse. We take this viewing angle as the angle of the ellipse. At the helping angle of view, we see a square circle, and at less than the helping angle, we see an ellipse at a different angle, so that in the end we see a. degree ellipse (i.e. a strip of hired color beauty). It is not difficult to understand this technique of drawing ellipses, but it is not easy to master the drawing of ellipses.
For an ellipse, it has two axes:the long axis and the short axis. The short axis divides the ellipse into two equal parts by the shortest path; the long axis divides the ellipse into two equal parts by the longest path. The long and short axes intersect vertically.
This is shown in Figure 1.
So how do you use the long and short axes to draw an ellipse?
Looking at Figure 2 above, the ellipse has an outer tangent square on the outside, and after drawing the square, we find the center of its perspective by drawing the diagonal of the square, and by looking at the long and short axes of the ellipse, we find that the short axis of the ellipse passes through this center while the long axis does not. We also find that the ellipse . . is tangent to the center of each of the side lines of the square. This gives us a symmetrical shape, the ellipse, and places it in perspective.
Looking again at Fig. 3, we get the same effect whether the ellipse is rotated or stationary. It is clear from this observation that the long and short axes play a considerable role in drawing the ellipse. Since the short axis of the ellipse goes all the way through the center of the square, we can use this to our advantage. This is exactly why I didn't recommend using the long axis to draw ellipses in the first place.
Keep practicing drawing ellipses and don't worry about positioning them in perspective. For example, in the image below are several ellipses drawn at different sizes and at different angles. After drawing the ellipse, determine the short axis of the ellipse by drawing a line through the narrowest part of the ellipse and dividing the ellipse into two equal parts.
Fold the ellipse you drew along the short axis; correctly, the two halves of the ellipse will just overlap, otherwise they will not. This is shown in Figure 4.
If you feel good about the ellipse you've drawn, you can pinpoint the short axis and begin to position the ellipse in perspective. At first, draw some simple straight lines as the short axis of the ellipse, and then try to draw ellipses of different sizes and angles. This is more difficult than drawing the ellipse first and then determining the short axis.
Then draw two converging straight lines and then draw the ellipse so that the ellipse is tangent to each line. One of the most difficult exercises is to draw the subcube and then draw ellipses on each face so that they are tangent to the side lines of each face, as we did for the drawings in Figures 2 and 3. Also, drawing concentric ellipses is a good exercise.
You can use reference lines to correct ellipses, but it's best not to draw ellipses with reference lines, and try to draw them directly by hand. If you keep practicing ellipses for a while, you'll find that your overall ability to draw will improve greatly.