The basic skill of an artist in academic drawing is the ability to depict the simplest volumetric geometric shapes on a plane - a cube, a prism, a cylinder, a cone, a pyramid and a ball. With this skill, you can build more complex, composite volumetric forms of architectural and other objects. A prism is a polyhedron, two faces (bases) of which have the same shape and are parallel to each other. The side faces of the prism are parallelograms. According to the number of side faces, prisms can be three-, four-sided, etc.
It is necessary
- - drawing paper;
- - simple pencils;
- - easel;
- - a prism or object in the form of a prism (wooden block, box, casket, part of a children's designer, etc.), preferably white.
Instructions
Step 1
You can construct a prism by inscribing it either in a parallelepiped or in a cylinder. The main difficulty in drawing a prism is the correct construction of the shape of the two faces of its base. When drawing a prism lying on one of the side faces, there is an additional difficulty in observing the laws of perspective, since in this position the perspective reduction of the side faces becomes noticeable.
Step 2
When drawing a vertically located prism, start by marking its central axis - a vertical line drawn in the middle of the sheet. On the axis line, mark the center of the top (visible) face of the base and draw a horizontal line through this point. Determine the ratio of the height and width of the prism using the sighting method: look at the nature, covering one eye, and, holding the pencil in outstretched hand at eye level, mark the width of the prism visible from your point of view with your finger on the pencil and mentally put this distance along the line of the height of the prism a certain number times (how many times it will turn out).
Step 3
Measuring the segments with a pencil already in the drawing, mark the width and height of the prism with dots on the two lines drawn earlier, observing the ratio obtained. Draw an ellipse around the center of the top face. Try to accurately convey its imaginary shape, looking at nature. Draw about the same ellipse (but less flattened) in the plane of the lower edge of the prism base. Connect the resulting ellipses with two vertical lines.
Step 4
Now, on the upper ellipse, you need to mark the segments of the intersection of the side faces and its bases. Looking at the nature, mark the points - the vertices of the polygon - lying at the base of the prism, as you see them, and connect them sequentially together. From these points, draw lines down to the intersection with the lower ellipse. Connect the resulting intersection points as well. As you draw further, the faces that are invisible from the selected point of view are erased or shaded, so draw all auxiliary construction lines without pressure.
Step 5
Draw the prism lying on its side using the auxiliary parallelepiped. Focusing on nature, draw a parallelepiped, observing the principles of perspective - the lines of the lateral edges, when mentally continued to the horizon line, which is always at the level of the viewer's eyes, converge at one point. Therefore, the farthest (invisible) face will be slightly smaller than the front one. Use the arm's length (or sighting) method when determining the aspect ratio of the box.
Step 6
On the front and back square faces, mark the vertices of the polygons at the base of the prism and draw them. Connect these points in pairs on two faces - draw the side edges of the prism. Delete unnecessary lines. Highlight the lines of edges and corners of the prism closer to you more thickly, and mark the distant ones with light lines.
Step 7
Looking at the nature, determine the angle of incidence of the light, the lightest, most shaded edges and, using shading of different intensities, convey these light ratios in the drawing. Draw a drop shadow from the subject. Underline the border of contact between the prism and the table with the darkest line. Please note that the light reflected from the table surface (reflex) falls on the most shaded edge of the prism from below, and illuminates it slightly. When applying shading to this edge, take this effect into account and apply a less intense tone in the place of the reflex.
